Hiram Percy Maxim (1869-1936) was the offspring of the inventor of the world’s first modern machine gun, Hiram Stevens Maxim. H. P. Maxim started developing one of the world’s first modern metallic firearm silencers, shortly after the dawn of the 20th century.

The nature of supersonic (beyond the speed of sound) gas flow from a firearm’s discharge was not totally understood by scientists in the early 1900s. They did not have ultra high-speed photography available back then, and they did not understand how a flow of supersonic propellant gas would create a loud gunshot noise. Regardless of this, Maxim did understand that the sudden and violent exit of high velocity propellant gas from the muzzle of a firearm was directly responsible for the loud noise associated with gunshot discharges.

We in a more contemporary world now realize that most physical objects moving through our atmosphere at a rate of speed beyond 1,100 feet per second (fps) will create the phenomenon known to the world as sonic crack. The tip of a leather whip, when snapped rapidly, moves at a rate of speed beyond 1,100 fps, creating its own sonic crack. A bullet moving beyond 1,100 fps creates two similar sounds, one from the front and one from the rear. Surprisingly, human ears can hear both sounds and discern them, one from the other, if the mind concentrates hard enough.

In today’s world, a common U.S. military M16 rifle discharges a 62-grain bullet at a velocity close to 3,000 fps. The mass of propellant gas, being much lighter and extremely elastic, leaves the muzzle of that same firearm at roughly 16,000 fps – many times beyond the speed of sound. It is not widely known, but the energy of exiting propellant gas from a high-powered rifle constitutes roughly 90% of the force available, while the bullet represents but 10%.

A mass of exiting propellant gas forms or gathers into a hardened front resembling a curiously rounded, elongated disc – known to ballistic scientists as a Mach disc. With a .308 rifle, that Mach disc is close to 5 inches in diameter, and it actually turns into a solid state for a fleeting moment. The supersonic disc projects a very loud noise in all directions, like an extremely loud speaker. That violent impulse of sound is so loud and so powerful that it can and will cause permanent hearing damage to any unprotected individual in close proximity.

Most firearm discharges form Mach discs. With a .22 LR rimfire pistol the exiting gas (only about a grain in weight) forms a smaller, elongated Mach disc well under an inch in diameter. Even though the smaller Mach disc is very temporary (less than 6/1,000 of a second in many cases), it causes an impulse sound that is so loud that it too will also cause permanent hearing damage to those unprotected ears in close proximity.

It is extremely unlikely that Maxim knew what a Mach disc was in the early 1900s, but he soon figured out that he had to first capture and then slow exiting propellant gas from a firearm in order to silence its report. Maxim used soft, malleable iron to form gas shearing baffles of various shapes, using stamping procedures and stepped metal forming technology. A brilliant engineering graduate of The Massachusetts Institute of Technology (at age 16) Maxim experimented with different techniques and baffle designs for capturing the violent blast of gas discharge – thus confining the (still unknown) Mach disc and slowing the velocity of the remaining gases below the speed of sound in air before they exited. His vision and hard work were eventually rewarded. At the age of 40, Maxim was awarded U.S. Patent No. 916,885 for his Silent Firearm, on March 30, 1909.

Maxim’s patent and deceptively simple baffle design resulted in a silencer about 1.35 inches in diameter by a touch under 5 inches long. Because all firearms of the day used relatively low, open sights, he developed his silencer with an unusual eccentric design that didn’t occlude the view of iron sights on rifles and pistols.

The Maxim Model 1909 silencer worked extremely well on .22 rimfire rifles, since they achieved a fair (but subsonic) bullet velocity with relatively low terminal gas pressure. The .22 caliber lead bullets of the day were covered with beeswax mixed with animal fat, which tended to protect a rifle’s bore. Highly corrosive materials in the priming and propellant gas required that a Maxim silencer be removed and boiled in soapy water after each and every use. It then had to be drained, dried and re-oiled to prevent destructive corrosion. Most of the early Maxim silencers have been ruined over the years because they lacked this high level of care. Almost all ammunition in the 21st century is now loaded with non-corrosive priming compounds and propellants, which currently negates the need for extreme care. Crud will continue to build up in .22 caliber silencers, but it will at least be non-corrosive crud.

The use of the 1.35 x 4.5-inch Model 1909 Maxim silencer on .22 rimfire rifles was very successful, but there must have been problems with rotation (clocking) of the narrow part of the can so that it could be nearest the top side of the weapon to which it was fitted. A silencer gets most of its axial alignment from mating with a shoulder at the base of threads on a barrel, with rotational alignment being almost an afterthought, initially. Rotational alignment is a real problem with an eccentric silencer, however, and thread wear (or QD coupling wear) eventually causes more and more rotation to occur. Thus a can that was properly affixed when new would eventually have the thicker side of its body intruding into the sight plane as threads and seat wore with use. Maxim provided an adaptor of hardened steel, with interrupted threads. This allowed the silencer to be easily attached and removed.

A perceived need for a thinner silencer design soon led to the adoption of the 1910 Model, which was about an inch longer in the body, smaller in diameter and considerably less effective. The longer, thinner 1910 Model silencer worked fairly well on both pistols and rifles, but it is not considered as desirable as the earlier 1909 model by suppressor cognoscenti. Again, the longer 1910 Model is much louder than the shorter, fatter, eccentric 1909 Model. An open space (containing no baffles) at the rear of the 1909 Model makes it more effective on a .22-rimfire rifle, but it still performs very well on a pistol.

Both models of silencers were sold by mail order, for about $5, a considerable sum back then. They shipped directly in a sturdy cardboard mailing tube with a metal screw cap, and with a U.S. postage stamp pasted directly on said cardboard tube. While the silencers were easily obtained, they required careful threading on a gunsmith’s lathe to prevent destructive baffle strikes by bullets. Major firearm manufacturers of the day sold weapons with factory-threaded barrels to accommodate Maxim silencers. Maxim also made hardened, interrupted thread couplings with shims that could be driven onto the ends of non-threaded barrels with a mallet. These fittings sometimes lacked accuracy because most barrels were not of standard and true dimension, but they did help with the difficult problem of rotational alignment. In truth, the fitting and installation of threads or a coupling by a gunsmith probably took a lot more time than it took the Maxim factory to actually manufacture the silencer itself. Few gun barrels are truly straight and concentric, especially those built in the early 1900s.

As the silencer industry progressed, quiet shooting became widely accepted. One was considered rude if he did not silence his firearm to avoid annoying family and neighbors during target practice. Finely crafted, stained and varnished Maxim boxes were filled with sand and used as indoor target backstops, so that target practice could be held indoors on special occasions and during festivities. The two-chambered boxes contained sand in the rear chamber to stop bullets. Densely packed rags in the front chamber kept the sand from leaking out. A replaceable wood panel in front kept the rags in place, and also provided a surface for mounting a target face.

Maxim and his silencers had a pretty good run for about 25 years. In the early 1930s, during the depths of the Great Depression, the U.S. Congress suddenly took it upon itself to ban all pistols in the country. This gun-grabbing act led to citizen anger and a massive public outcry. It resulted in a widespread and massive political correction during following congressional elections. The pistol ban was struck down in federal court, and quickly reversed a couple of years later. Unfortunately, some of the guilty legislators had another few years to run before their terms were up, and in 1934 they passed the National Firearms Act, which placed a restrictive tax on machine guns, shortened long firearms and a few related items.

This sudden legislative move in 1934 proved to be a devastating blow to the Maxim Silent Firearm Company. Fortunately for the survival of the company, it had already moved into the area of silencing internal combustion engines for motor-driven vehicles. Hiram Percy Maxim died a little more than a year later, from a very sudden illness.

Very few of the original, fragile, 1909 Maxim silencers exist today, most having been destroyed through loss, mishap, ATF confiscation or corrosion. Even though the Maxim silencer technology is over 100 years old today, it is still very good technology, and surprisingly effective in our contemporary world. It is interesting to occasionally use the historic Maxim 1909 silencers and compare them with what we have available today, since they are still quite competitive when used with subsonic rimfire ammunition and moderately long barrels.

The Maxim 1909 Model Silencer and Related Notes:

According to respected silencer expert Al Paulson, all of the original Maxim papers, patent drawings and original inked drawings remained in the hands of Maxim’s New York City attorney, who died many years ago. These were put into sealed storage in cardboard boxes in an attic of a law office in NYC, and only came to light about 10 years ago. At that time they were offered for sale for a handsome sum. I have not followed up on what became of them. I believe that they still exist, somewhere, and that the collection was not broken up. There is another collection of Maxim papers residing in a State Museum in Hartford, CT.

The original Maxim 1909 .22 LR silencer was said to have been the most effective of all of those built by the Maxim Company. It is easily the equal of many of those built during the 20th and 21st centuries. According to Al Paulson, the 1909 measured 4.88 inches in overall length by 1.35 inches in diameter. The main tube is a scant 4.55 inches in length. There is a 3.77-inch long groove pressed into the bottom of the dead soft tube, as a sort of key used to hold the baffles upright. The rear thread size is typically 1/2-20, RH. It weighs 6.8 ounces. In the past I have been able to examine an original Model 1909 that was attached to what apparently was at one time a Quackenbush .22 LR rifle, turned into a pistol and used for many years in a slaughterhouse. According to Al Paulson, the unit turned in a respectable 118 dB sound level when tested with 40-grain subsonic .22 LR ammunition on a pistol. The Model 1910 tested at 126 dB.

The Maxim 1909 used flat baffles with a deceptively simple, tiny scoop stamped into the rear face of each baffle with a punch. When used in combination with the eccentric design, the tiny scoops forced incoming propellant gas into the lower section of the eccentric can between each baffle. The 1909 Model was and still is remarkably effective. The two proximal (rearmost) baffles are of a thicker material and are about 3/8-inch apart. The rest of the baffles are about 1/4-inch apart, quite thin, and they go all the way up to the front end cap.

While brilliant in design, authentic Maxim construction is fragile. Maxim silencer construction was crimped, and it was definitely not solid. The dead soft metal in the main tube or body has very low tensile strength and little resiliency. Dropping the can on a hard surface could definitely injure alignment.

I am indebted to Al Paulson for clarification of a number of conflicting issues and information relating to the Maxim Silent Firearm Company. Because of the 100-year elapsed period of time there have been more than a few facts and events that took knowledge and research to reconfirm.

The light .223 bullet needs substantial velocity in order to work effectively. Initially the boat-tail round was designed to be marginally unstable, spun with a slow 1 turn in 14” twist. It tumbled on contact, breaking in half at the cannelure and causing two jagged wounds in one. Unfortunately the slow barrel twist caused problems in cold temperatures. Under Arctic conditions the weapon wouldn’t stay on a dinner plate at 25 yards. Eventually a faster twist was adopted. NATO trials were held in Europe, where it became apparent that a more streamlined, heavier bullet would be more accurate and more effective at longer range. The standard round was lengthened and streamlined, resulting in the 62-grain bullet we have today. The 62-grain bullet needs at least a 1 in 9” twist. The long-range 70, 75 & 80-grain bullets need a 1 in 7” twist in order to work effectively at all temperatures. LE personnel and civilians are not bound by the Geneva Accord, hence may use any bullet that will do the job (within their own legal limits, of course). Loaded ammunition is currently available in weights ranging from 40 to 150 grains, with 80 grains being the upper limit for lead-cored supersonic projectiles.

Heavier .223 bullets are more strongly constructed, and will penetrate fairly well. Lead melts at 700 degrees F. On a warm day a lead-cored bullet will easily reach these temperatures from the combined influence of bore pressure, bore friction and air friction. Lightly constructed varmint bullets often blow up on the way to the target, as they were never intended to spin as fast as 337,000 RPM (in a 7” twist barrel), and should not be used. A number of police departments have adopted the 40-grain bullet for use in entering trailers and apartments, as this light bullet typically dumps its energy quickly, and tends not to penetrate as many walls beyond the primary target. A light .223 round is preferred over a 9mm or .40 S&W round, as it will not penetrate walls as easily. Its effect during a headshot is devastating and instantaneous. Hornady builds TAP (tactical application, police) .223 (and .308) rounds in assorted weights that are designed to function in enforcement applications. We have not tested these extensively, but plan to in the near future. Jeff Hoffman of Black Hills Ammunition Co. favors their 60-grain softpoint bullet as an all-around, .223 enforcement and hunting projectile. It is a tough bullet that opens well into a classic mushroom, and tends to stay within the primary target. It is very accurate and very versatile. Ammunition manufacturers are very responsive of late, and are struggling to give the industry anything it will perceive as better. Other rounds that come highly recommended are Federal and Winchester’s 69 grain JHP, and Black Hill’s 68 and 75 grain JHP. If you have a Vietnam-era M16 with an older barrel with a 14” twist these longer bullets will not stabilize. They will tumble end-over-end as soon as they get out of the muzzle. One must have a barrel with a 9” to 7” twist for the heavier bullets.

For a JACKETED, SUBSONIC ROUND in suppressed weapons we like Speer’s 70-grain semi-spitzer, soft point, as it comes closest to a round-nose, flat-base bullet. These are not yet available as loaded rounds. Loaded subsonic .223 ammunition is currently available from E B R at 512-360-5327, and H J B R at 256 447 1987. It will eventually be available from Black Hills as well. The point of impact (POI) of subsonic rounds will be different from supersonic rounds (usually much lower and a bit left) because of different recoil characteristics. Some who use both rounds in the same weapon use an optical sight for high-powered ammunition, while the weapon’s iron sights are adjusted just for subsonic rounds. While expanding the versatility of the weapon, subsonic bullets out of a suppressed weapon typically do not have the energy to do much upon hitting a target. Another sighting technique is to use the lower part of the vertical part of a duplex crosshair as the aiming point for subsonic ammunition. Extensive practice is recommended to achieve familiarity with both types of ammunition. Again, don’t expect very much performance out of subsonic .223 ammunition, as there isn’t much energy involved.

Aguila currently distributes a .22 LR round that weighs 60-grains. These do not work very well in M16s that have been temporarily modified with a Ceiner conversion kit. They jam, and a single round loudly dumps its gas out the breech because the shell is very short. Subsonic 40-grain ammunition works in the conversion kit, but the kits have to be polished and reworked in most cases. They must be kept clean and well oiled for any sort of reliability. Subsonic ammunition delivers a small fraction of the energy to the target, but the sound level from a suppressed weapon is virtually undetectable. Supersonic ammunition is more fun, and unlike subsonic, will cycle the M16’s action reliably. Coconuts, tomatoes, cabbages and water-filled jugs make interesting targets, especially with some of the hyper-velocity varmint rounds.

Remember that hot weather will increase pressures and velocities, sometimes to the point where non-crimped primers fall out of fired, commercially loaded cases, tying up the action. We wouldn’t be mentioning this if it weren’t a problem, especially in those AR15s that have been “protected” with a steel anti-auto block in the receiver. It is during hot weather (or in a very hot barrel) that chances are greatest that the lightest weight, hyper-velocity ammunition will come apart in the faster 7” twist barrels. When this happens, the rounds will turn to copper foil and droplets of molten lead in the air. They will not retain their integrity, and will not strike a target.

For law enforcement use the M16 with a 14.5”, heavy barrel (H-BAR) represents the best compromise. There is enough length for reliable functioning and adequate ballistic performance, yet the weapon is still short enough to be handy. Some in LE are uncomfortable about the fact that either a short 14.5” barrel or the full-auto M16 constitute restricted, NFA weapons. There is some merit in the fact that, if a police duty weapon is used in a raid, and if it is a machine gun or NFA weapon, some bad press or legal problems could possibly ensue. The AR15 with a 16” barrel will neatly sidestep this issue. Both the 14.5” and the 16” barrels are short enough to be handy. The general public has seen the M16 for over 35 years. They are thus conditioned to its presence and view it as an “old” rifle, which is a positive public relations feature. Weapons that are smaller in stature are perceived as less dangerous than physically larger weapons. If the M16 is hanging by its sling against the side of an officer’s body in a muzzle-down position it will be perceived as less threatening (by the general public and press) than if it is brandished or carried in the ready position on the way to deployment. Loudness of the .223’s intense report is also an important public relations concern, and less noise is always better than more noise. A small silencer is a useful accessory, as is a flat-topped, receiver with a rail. If a scope is used the flat-topped upper and a gas block without a front sight tower are both quite useful. A scope mount that attaches to a carrying handle offers versatility, but puts the sight radius so high above the stock that it is awkward and uncomfortable to use. A flip-up rear sight is a handy backup for an ACOG sight, and both can be used together at the same time. SIGHTS THAT REQUIRE BATTERIES WILL OFTEN NOT WORK WHEN THEY ARE NEEDED, AND SHOULD NOT BE CARRIED UNLESS CHECKED CONSTANTLY. Don’t be lured by the apparent ease of use of these sights. All one has to do is forget to turn one off, and it will be absolutely useless a week later.

Curiously, flash hiders are perceived as silencers by the uneducated general public, as are tactical lights that look like they would work as silencers, even though they are not attached to the end of a barrel. Both the 14.5” and the 16” barrels cycle an action reliably. Both barrels will deliver powerful and accurate fire up to about 300 yards. These two barrel lengths make the M16 or AR15 very useful entry guns for raids and hostage rescue. The only barrels we endorse are 14.5” and 16” H-BARs, although we know that many have had very positive experiences with the short 11.5” barrels.

The military designates the weapon with its flawed 14.5” barrel the M4-A1. Curiously (and unfortunately) the rear portion of the standard M4 barrel is turned quite thin, at a touch over 5/8”. WE VIEW THIS REDUCTION IN DIAMETER AS A REAL MISTAKE, AS THE THINNER BARREL LACKS THE ABILITY TO REMAIN RIGID AND ABSORB HEAT LIKE THE H-BAR. The M4-A1 barrel was designed for a grenade launching attachment, and for this process a deep groove was cut forward of the front sight We feel that the reductions in barrel diameter seriously degrade the weapon’s accuracy potential. Dr. Philip Dater at Gemtech used such a barrel in the testing of his cans, and had his barrel bulge at the groove in front of the sight tower. Heat was probably a factor, combined with pressure. The bulge did not diminish the accuracy potential of the weapon. We are told that Colt delivers only this barrel with their version of the M4-A1. One can buy M16s and AR15s from Bushmaster or other manufacturers. Upon request they will provide them in the short H-BAR configuration without the offending rear reduction and groove in the barrels. Buy the weapon in the configuration you desire. An LE agency should not significantly alter weapons after they are purchased, as that may turn into a point of contention in court after a shooting. CYA.

It is said that Bushmaster makes the best weapons in the business today, although Colt has the reputation, having been in the business for over 160 years. The Commando-style, sliding buttstock is flimsy, but does offer a temporary 4” reduction in overall length. It is painful for anyone with a beard to use. We recommend the solid, plastic buttstock with a rubber buttplate instead, in the shortest version possible, and without a butt trap. This stock is steadier and more workable, yet still provides enough shoulder room for web gear and body armor. If you already have an M4-A1 with the defiled barrel, Bushmaster and other manufacturers will sell you a drop-in, match quality, post-ban (unthreaded) replacement barrel with all the hardware (barrel nut, gas tube, forearm and front sight group) for roughly $200. An LE agency should send the entire weapon in for modification and replacement of critical parts. Test the weapon extensively upon its return. CYA. A 7” twist is preferred only for long distance shooting with very heavy 70 & 80-grain bullets. The 9” twist is more desirable, as it is considered to be more versatile. Cartridges containing sharply pointed 70 and 80-grain bullets will not fit in standard magazines, and must be loaded into an M16’s port individually, by hand. This of course reduces a machinegun to a single shot, hand loaded rifle. Most Colt and Bushmaster barrels have chrome-lined bores. While not normally quite as accurate, chrome-lined bores are less susceptible to corrosion and wear, a consideration for a weapon that may only be cleaned infrequently.

When a law enforcement entry team is inside a building the members usually have one or both ears unprotected in order to hear the movement of suspects. Firing an unsuppressed M16 in a confined area is not only extremely painful and damaging to unprotected ears, it also destroys an officer’s ability to hear the continued movement of suspects. The report is so severe that perpetrators and officers have been found to be bleeding from the nose and ears if a .223 round was fired inside a room that they occupied. The flash from an unsuppressed weapon can also blind a shooter temporarily in a darkened environment. We strongly recommend that the AR15 or M16 be equipped with a small, compact sound suppressor to take the edge off the severe blast, and the sometimes substantial flash. A good flash hider of the vortex type will remove muzzle flash, but the felt report will be louder to the shooter’s ear. The down range report may be lessened to a substantial degree by some flash hiders and muzzle brakes. The assault rifle ban hasn’t helped us with regard to sound suppressors. It is not currently legal to mount a silencer or a flash hider on an AR15 with a post ban receiver, hence the rising value of pre ban lower AR15s. The receiver is of course the critical part, and listings of serial numbers are somewhat available to help determine which receivers are pre or post ban. BATF hasn’t made a serious effort at prosecution yet, but the day may come. The current unwritten rule of thumb is, if a prosecution will make headlines, BATF will make the effort. Again, law-abiding citizens and businesses are much easier to prosecute than criminals because they stand still and cooperate.

While there are a number of quick-release couplings on the market, we recommend the time-honored screw connection. Here’s why – the standard barrel threading at the muzzle is 1/2-28, which means that the very end of the barrel has been reduced to a mere 1/2” in diameter, and at the root of the threads the diameter is less than 7/16”. The grooves at the base of the threads act as stress concentrators, helping to propagate tears or cracks in the parent metal. While that threaded stub may be adequate for a flash suppressor, it is barely adequate as a base for a longer, heavier sound suppressor, which generates a considerable forward pull with each shot. The pull is very sharp and very strong, and in our view the small 1/2” thread is doomed to eventual failure if enough (2,000 to 10,000) cycles are loaded onto it. All or most quick-release couplings rely on a flash suppressor or lugs as a base for the connection. Ultimately one has everything hanging on a threaded, 1/2”-diameter stub with a .224” diameter hole in the center of it. Given the opportunity we would always opt for heavier threads. During the strain of a forced entry an officer may end up using his weapon as a punch or ram, and a heavy mount on a heavy barrel will more easily handle that strain without damage. We know you are not supposed to do that, but it happens. When one screws a can onto a heavy mount he knows it’s solid. It takes about 15 seconds to install a can on a threaded connection. Simplicity in this case is a virtue. A quick-release coupling is often weak, and sometimes not reliable. We have seen a can launch down-range more than once because the coupling either gave out, because the lugs weren’t properly seated, or because-the system loosened — allowing axial misalignment and bullet strike. The third sin of the snap-on coupling is not releasing on command. Corrosion, carbon buildup, or the failure of the spring-tensioner/piston has been known to cause the system to seize up. Accuracy problems have been traced to quick-release couplings that shot or wore loose, allowing slight baffle contact. Barrels have been bent and cans have been destroyed while trying to get frozen couplings to release. These couplings usually work fairly well when they are new and freshly greased. Shoot through one several hundred times and put it in the trunk of a cruiser, wet. Leave it there, unattended, for a few months in southern Florida. Humidity combined with heat will almost guarantee corrosion/seizure problems.

If we were given an unthreaded, heavy match barrel (H-BAR) we would probably turn and thread the muzzle at 11/16” or 3/4” NF, LH rather than 1/2-28. Indeed, if the 3/4” diameter of the hole in the front sight tower were not an issue we would machine a heavy flange near the barrel’s muzzle and install 3/4” or 13/16” – LH threads at the muzzle for a more serious attachment point. While a two-point mount may be more secure, it is more likely to seize up than a single-point mount. When a two-point mount seizes it is extremely difficult to get penetrating oil where it is needed. A large, single-point mounting system may be non-standard, but it is far stronger and more rigid in all respects. The industry trend is toward single-point mounting systems, as they tend to be inherently trouble-free if made large enough to handle the stress of firing and abuse. Left-hand threads tend to self-tighten at the muzzle, while right hand threads tend to loosen in reaction to barrel torque as each bullet is spun in a right hand direction. That doesn’t necessarily mean that LH threads will always stay tight, but they don’t tend to loosen as easily as right hand threads. A suppressor needs threads to pull on and a shoulder to rest against or it will not stay in line with the bore. The threads tend to center the can axially, while the shoulder holds and controls angular alignment (as long as the can remains tightly screwed in place). If the threads and shoulder are very close together the system is referred to as a single-point mount. If the threads and shoulder are from 2” to 10” apart the mounting system is referred to as a two-point mount, and here the threads are usually buried deep inside the center of the can. Both types of mounting systems will compensate for the considerable amount of wear that occurs as a can is screwed on and off its barrel. Wear occurs from three main sources. First, the intense forward pull following each discharge applies considerable stress to the threads. Second, ground glass particles from the priming materials are thoroughly distributed over the thread surfaces. Third, the high mechanical advantage of threads also applies a lot of force to all surfaces. This is why we prefer large diameters and a generous shoulder or flange, so that wear will not be as significant. Cross threading is occasionally a problem, and the only cure for a butchered thread is to cut the barrel off and re-thread it properly. The bottom line in all of this is that a simple, single-point, threaded mount of massive dimension will provide the best service with the least amount of trouble. If left-hand threads are used the rear of the can should be stamped LH to eliminate confusion for those who can read.

It has been mentioned that post-ban barrels are typically shooting more accurately than pre-ban barrels. This is probably due to the fact that pre-ban barrels are turned down to 1/2” diameter at the muzzle. Most barrels are button rifled, and the rifling process puts a lot of internal strain on the barrel metal. Turning the outside diameter thin reduces that strain, and has the effect of enlarging the bore at the muzzle, which is the place where the bore should be the tightest, not loosest. As far as accuracy is concerned, the best results will occur when the barrel is thickest at the muzzle. Many European target weapons are built that way, but the practice never caught on in the U.S. Putting a can on a muzzle does stabilize it to some degree, but it doesn’t usually tighten the bore at that point. Accuracy problems have been traced to asymmetrical blast baffles and to baffle apertures that were too tight to allow bullets to pass without striking. One last thought with regard to the small 1/2-28, threaded barrel stub – if a flash hider or a sound suppressor is screwed on too tightly it can have a detrimental effect on accuracy. This is of little consequence on an entry weapon, but can be a problem on a varmint rifle. The tightness of the can or flash hider will not be as much of an issue if the threaded muzzle stub is of a substantially larger diameter.

The .223 is such an intense cartridge that heat gain becomes a problem when a suppressor is attached. The more effective and the more compact a can is, the greater the heat gain. While rapidly shooting 20-rounds of military ball ammunition won’t present a problem, 50-rounds might. In combat, we feel that one should use carefully aimed shots and be conservative with ammunition.

Because water is a major byproduct in the combustion process, a good deal of it will get trapped in a suppressor. A suppressor should be removed and allowed to air dry after each firing session. The internal baffles and the threads should be lightly oiled or greased to protect them from corrosion. We use TSI 301, Corrosion-Bloc, Boeshield T-9, or RIG (rust inhibiting grease). RIG will vaporize and leave a cloud of smoke in front of the weapon, which could cause a problem in some circumstances. Left-hand threads are good here, as they don’t loosen as easily during firing. A suppressor will rust in place it the moisture aspect is not attended to. The rear part of a two-point mount acts like a seal against the slight swelling of the barrel just forward of the front sight tower. It will wear a bit with each use, and the seal will get better. The seal between the front sight tower and the gas port in the barrel is often less than perfect. High-pressure gas leaking here has been known to cause some amount of noise. A small bit of J B Weld applied before assembly will help. If you do this be sure that none gets into the barrel port or it will prevent proper cycling. Always store the weapon in a level position, or point it muzzle-down, with the action locked open. Do not store the weapon pointing up, as gravity will cause dirt and particles to fall downwards and lodge in the action. If the action is locked open, air movement will help dry accumulated moisture.

If suppressors are used, we believe that one should sight in and practice with them in place. It will not do to carry a suppressor in a pouch, to be used if one feels it might be beneficial at the time. Any weight placed on the end of a barrel will change its point of impact A can should be removed for cleaning, drying and oiling after every use. A can should remain in place during training and deployment. The weapon should be sighted in with the can in place, as the weapon’s point of impact will be different without that added muzzle weight. A weapon should not be fired without either a muzzle brake, a flash hider or a suppressor screwed on to 1/2-28 threads at the muzzle, as those threads have been known to expand without the support those devices offer to the thin, threaded area. The muzzle crown may expand, and the devices won’t screw back on later. This is not a common problem, but it occasionally does occur.

A properly designed and mounted suppressor typically enhances accuracy. The weight of the can will stabilize barrel movement. The reduction of recoil and report make the weapon much more comfortable to shoot. While these little rifles are primarily used at close range, they are also capable of being very accurate at longer distances. With a proper sight and a skilled marksman headshots are definitely viable at 100 yards. Iron sights are normally adequate on the M16 carbine. They are compact, durable and battle proven. An attached tactical flashlight with a pressure switch on the forearm is a useful accessory, although it certainly can reveal one’s position.

In order to cope with the increasing violence in today’s world the law enforcement community continues in its search for more effective weapons and tactics.  A recent study on the subject in the U.S. revealed an 87% miss rate with an officer’s duty sidearm in the heat of contact.  Put another way, when an officer was forced to use his duty pistol in defense of life, 87% of the rounds expended under stress failed to strike the attacker.

Sequentially, the high miss rate causes two problems: 1. The unharmed perp remains free to continue his assault. 2. The rounds that missed may impact innocent bystanders, with severe painful, moral, emotional and legal ramifications.

For those who have been there, the emotional stress of being in combat causes peripheral awareness and fine motor control to vanish. For most, there is a significant difference between shooting at paper and shooting at a human being who represents a threat.

Before we get into the Ruger carbine, it might prove useful to look at a bit of history and precedent. Since the days of the U. S. Civil War (called the War Between the States in the south) it has been recognized that a firearm which is held and sighted like a rifle is inherently more accurate than a pistol. For those who desire specifics, a rifle is on the order of 16 times more accurate than a pistol. This is very apparent in the rough and tumble atmosphere of CQB. A rifle’s greater accuracy is due primarily to the way it is held and sighted, since barrel length (within reason) means little in terms of accuracy. A five or ten inch barrel is capable of delivering accuracy greater than or equal to barrels approaching 30 inches in length. With regard to power, a pistol cartridge is capable of developing most of its energy inside a five-inch barrel, and doubling barrel length will typically add a mere 10% to the velocity. Increasing its length to 18-inches, the legal minimum in Canada, will usually reduce velocity over that achieved with a five-inch barrel.

Some in the Civil War carried short carbines with barrels between 12 and 14 inches in length. In 1934 American legislators levied an (at the time) excessive $200 tax on carbines with barrels shorter than 16 inches. The result of this single action effectively stifled the development of truly compact carbines in the U.S.

Here we are, almost 70 years later, and our nation’s squad cars are primarily outfitted with pump action, 12 gauge shotguns. While I happen to like shotguns, they are often too much or too little. When used with slugs they may go through both sides of an automobile. They will penetrate quite a number of walls in an ordinary house, and are capable of easily killing innocents within. It is for this reason that shotgun slugs are rarely issued for urban duty.

When used with buckshot against an exposed, unarmored opponent under 30 yards a shotgun may be effective. At greater ranges, against body armor, against heavy or heavily clothed opponents, against a drugged individual, or behind tempered glass, buckshot is often ineffective.
In a recent attempt to stop a dangerous felon in a moving car trapped within a closed parking lot in Georgia, police officers discharged 17 rounds of 12 gauge buckshot from their duty shotguns at the suspect as he attempted to back over them repeatedly with a small car. The shots were primarily fired from the rear, and none of the 153 projectiles managed to penetrate the lightly built Japanese vehicle. Most of the pellets skipped over the rear windshield to impact the walls and windows of nearby apartments. Again, none of the projectiles penetrated the vehicle effectively. In fact, when the vehicle was finally restrained the suspect was totally unharmed (by gunfire).

In another recent shooting in a wealthy southeastern community, an intrusion alarm was activated when three thieves entered a large metal building. This happened during a shift change, so double the contingency of officers responded, with sirens blaring. Two perpetrators were apprehended quickly. The third, a large, heavy man, ran to a nearby wooded area. As the perimeter tightened the man charged a large group of the responding officers, yelling obscenities and firing a pistol at them as he ran. Big mistake. The officers returned fire with their duty shotguns, charged with buckshot. Those who visited the scene later mentioned that an outline of the suspect could be seen against one wall of the metal building, caused by those pellets that struck the sheet metal around the suspect.

While the buckshot ultimately stopped the suspect, it was only the large quantity of lead that brought him down. At a nearby hospital some 160 pellets were removed from the suspect, while 55 were allowed to remain. Surprisingly, the wounds were not fatal, and the perp later stood at trial for burglary and assault with a deadly weapon.

Both Glock and Ruger have maintained a police carbine in a major pistol caliber in the design and prototype stages for many years. It took events like the FBI/ Miami Shootout and the ’88 Palm Bay (Florida) shootings to get the enforcement community to realize that pistols and shotguns are often not effective against opponents armed with accurate carbines. It only takes a single round to end most armed confrontations, but that single round must be properly directed. Unlike the carbine, a single shot fired from a duty shotgun will direct either 9 or 11 pellets down range, and a sworn officer may be held legally accountable for each and every projectile in a court of law.

I credit Col. Jeff Cooper with reintroducing the concept of snap shooting with a carbine. With practice, the snap shot from a rifle or a carbine can be very fast. Experience tells us that a rifle shot will be considerably more accurate than a shot from a pistol.

For many years Marlin has produced their Camp Carbine in 9mm and .45 ACP. While the Marlin Camp Carbine is short and handy, Marlin neither officially recommends nor endorses it for enforcement use. It is a bit fragile, and those used by departments have not held up well to heavy use. Then too, there is the occasional problem of the hammer on a Marlin Camp Carbine riding back over the center of effort of its spring, sticking there, and rendering the weapon inoperable until it is field stripped. This is a major liability in a weapon intended for combat.
Ruger has been smarting for years over the “Barbarian” from Austria who (biblically speaking) stormed into the midst of the U.S. with an accurate, lightweight, reliable pistol, and captured the extensive law enforcement market in this country. Glock had the opportunity to introduce their carbine as a companion piece to their pistols, using magazines that were interchangeable. For some reason Glock decided not to do this. Ruger does have a modest share of the enforcement pistol market, and eventually took the plunge, using interchangeable magazines as a major selling point. The concept is a sound one, but the battle among 9mm, .40 S&W and .45 ACP clouds the waters.
While at the SHOT Show in Vegas a couple years ago I visited Ruger’s booth and again spoke with their law enforcement representative, as well as two of the people responsible for developing and testing the police carbine. Eventually a Ruger carbine was sent to me for testing and evaluation. I wanted it chambered in .40 S&W, but received the loaner carbine in 9mm instead. Oh well…

Getting the stats out of the way, Ruger’s Police Carbine is short, rugged and handy, measuring a scant 34.5-inches in overall length. It has a 16-inch barrel, which is a surprise to me, as most of Ruger’s other carbine barrels measure 18.5-inches, so they can be sold in Canada. The stock is molded in reinforced Zytel plastic, and has a soft, grippy molded rubber buttplate on the rear. The trigger is heavy and positive, breaking at roughly 9 pounds. This is a combat weapon, and we don’t want an officer accidentally putting a round through a wall under the heat of stress. I actually like the trigger as stiff as it is. One’s finger softens the break-jump when part of the trigger disappears into the cast-in-place trigger guard. The safety is of the sliding, cross-bolt type, positioned directly behind the trigger. It is accessible and positive.
The actual length of pull is slightly more than 13.7-inches. Jeff Cooper’s preferred length of pull is 12.5-inches for a rifle. A pull of close to 14-inches is a bit long, since most officers will be using the weapon while they are wearing body armor, and that will increase the pull even more. I would like to see the stock shortened another inch, or even a bit more, to accommodate a vest and to allow faster handling. I am six-feet tall, and carry a lightweight, five-pound, .308 carbine with a 12.5-inch pull when I am in Alaska. Anything longer snags on clothing—slowing rapid mounting of the stock to the shoulder.

Ruger’s carbine carries sights which are adequate for the purpose, but which have deficiencies. The normal rear sight is a straight notch in a blade, moderately protected by slight bulge in the plastic barrel cover. A rear peep or ghost ring sight was carefully researched and worked out during WW II. Such a sight is carried on the M1, M1 Carbine, M14 and M16. It is rugged, fast and accurate. It is my feeling that the ghost ring style of iron sight cannot be improved upon, and Ruger does currently offer the ghost ring sight as an option. Ruger’s front carbine sight is a straight blade, integrally cast between two small ears to protect it. It is my feeling that the ears should curl more to each side, to prevent someone from accidentally using one of the ears as a sight instead of the central blade, which could cause a miss in the heat of battle. While this may sound like an unbelievably dumb thing to do, I wouldn’t be mentioning it if it hadn’t already happened on more than one occasion. The front sight is fixed, and it is pinned into position on a step on the front of the barrel. All of the sight correction has to be handled by the adjustable rear sight, which appears to have been taken directly off Ruger’s MK II, .22 LR target pistol. The rear sight is a bit fragile, and could stand some beefing up.

A Zytel barrel cover is held at the front by Ruger’s traditional cast aluminum barrel band. The flimsy cover is held at the rear by a spring clip that fits over two heavy cuts in the barrel’s breech, considerably reducing the barrel’s thickness at this point. Curiously, the muzzle end of the barrel is quite thick, while the rear is weakened and made quite thin. The main heat and pressure are generated at the rear, where the barrel should be thick. The muzzle end could actually be reduced in diameter. Overall, the rear of the barrel should be thicker than what it presently is, while the muzzle end could be turned to a thinner diameter. This is precisely the reverse of the way it currently is. Once again, cosmetics won out over strength and utility. This is not good on a weapon that is purported to be a police carbine and intended to be used in a rugged combat environment.

The cast steel receiver is an upper unit that houses an upper bolt. The upper bolt is connected by two heavy steel straps to a lower bolt that rides on a rod and a recoil spring in the forearm, bearing some similarity to the M1 Carbine and the Mini 14. Since this weapon is blowback operated, a considerable amount of weight reciprocates back and forth, divided more or less equally among the upper bolt, the connecting steel straps, and a lower bolt that rides on the rod beneath the barrel. It is a moderately efficient use of space, but not of weight. The sturdy stock weighs a little over two pounds, while the barrel and action weigh close to 4.5-pounds. When the weapon is loaded with a full magazine it weighs close to 8-pounds. Much of the considerable weight resides in the reciprocating mass of the bolt assembly.

The receiver hooks into a metal insert in the stock at the rear, and is held with a small screw through the bottom of the stock at the front. Slots in the top of the receiver will take the patented Ruger scope rings. I have known people who mounted a scope (and a suppressor in .40 S&W) on the police carbine, but a scope makes the weapon more fragile, and detracts from its use as a pistol-caliber carbine.

The weapon is fairly handy as it is, and is fairly accurate in rough-and-ready, offhand use. It will be considerably more accurate under combat conditions than a handgun. When put to use in a cruiser the carbine will either rest in a rack near the driving patrolman, or lie unused for months and rattle around in the trunk. The carbine has to be tough and reliable, and by-and-large, it is.

What would I change? First, the carbine is still too long for its intended use. I would cut at least an inch off the buttstock to reduce the pull, making it quicker and handier to shoulder. Then, I would shorten the fore end of the stock one-inch, and take six inches off the muzzle end of the barrel, finishing it at roughly ten-inches. That would then make the carbine an NFA weapon with an overall length of roughly 27-inches. By comparison, H&K’s excellent 9mm PDW (personal defense weapon) carries a six inch barrel, weighs about five pounds, and measures about 23-inches in length when its folding stock is deployed. While the PDW is an accurate weapon, I believe a modified Ruger Police Carbine would be even more accurate, as its stock is more rigid and more ergonomic.

I would thicken the Ruger stock in the wrist and action area. A plastic stock can be thick where necessary without paying a penalty in either material or weight, although the steel molding dies will have to be thickened to accommodate such a change. There are no sling swivels. While this weapon doesn’t need an ordinary sling, it does need some sort of carry or retention strap on its butt or grip, so an officer can hang or attach his weapon to his body while handcuffing suspects. Most departments have specific rules that mandate than an officer will never lay his weapon down while handling suspects. Those rules exist for a reason, and Ruger would do well to invest in a minimal strap retention system that works without being in the way.

If possible, I would reduce the reciprocating weight of the bolt to make the weapon a little lighter. I would then refine the front sight a bit, as mentioned earlier, and add a more rugged aperture sight to the receiver. And, of course, I would eliminate the nasty slices taken out of the barrel’s breech, thicken the rear portion of the barrel a bit, and taper the front slightly.

With intelligent refinement about two pounds could be taken from the barreled action, yielding a carbine that would be as accurate, yet lighter, shorter and handier. It would take a BATF Form 5 to transfer to a police department, yet these forms are free of charge and go through fairly quickly, supposedly within 20 days.

Both the barrel and the stock can be structurally considered as beams, and shortening will allow them to become automatically lighter, while retaining similar levels of strength. While a shorter 10-inch barrel will produce an energy level similar to a 16-inch barrel in a pistol cartridge, the strain on the bolt and buffer system will be lessened because the pressure curve will drop sooner. This may sound unreasonable, but we see it often when shortening barrels on blowback pistols and subguns. A cartridge doesn’t really release its hold on chamber walls until the pressure drops substantially. The heavier bullets found in .40 S&W and .45 ACP cartridges will increase the blowback effect over the relatively lighter 9mm bullets. A rubber buffer will be much lighter in weight, allowing at least a pound to be removed from the bolt.

In summary, in spite of its current shortcomings, I really do like Ruger’s police carbine. It is a sound concept that has been a long time in coming. It is still in an early stage of development and needs refinement. If the Mini-14 can weigh about the same, yet deliver over three times the energy, there is no reason why the police carbine can’t be refined to weigh considerably less than it currently does. Law enforcement has been slow to adopt the carbine. It hasn’t sold as well as it should have, and the weapon is now being released to the civilian market. Ruger has traditionally mandated that none of its NFA weapons will be released to Class III dealers. One result of this is that its compact 9mm subgun has sold poorly to police departments. Without dealers to aggressively hawk its wares few manufacturers will ever be able to sell niche products in a specialized industry. While Ruger continues to be the largest firearm manufacturer in the U.S., some of its products have been released without being fully refined and developed, and as a result have sold poorly. I hope that our comments are taken seriously, and that Ruger does refine its police carbine into a light, short, handy tactical weapon.

By Matt Smith

SAR’s Precision Shooting Editor is the owner of Sound Technology Inc, which specializes in accurized suppressed shooting systems. Roving reporter Matt Smith took a few minutes to interview Mark, hoping to bring some better information to light about this interesting Class 2 manufacturer.

SAR: Mark, tell us about your background? Where did you come from?

Mark: I came from a big family and grew up in a little farming community in Upper New York State. From a very early age I was interested in mechanical things. I was building functional boats and crossbows by age seven. When I got out of high school I went right into local industry, which in my case turned out to be the motor division of GM, near Buffalo, NY. I worked there a year or so and then moved to a nearby metal fabricating plant, where we built heavy industrial equipment. I worked there as a machinist on big, sixty foot lathes, huge metal planers and vertical boring mills. Everything was loaded with 40-ton gantry cranes, which moved on three miles of rails inside the facility.

SAR: How long did that last?

Mark: About seven years. After which I got a lecture from one of my uncles about going to college and getting a degree. They say timing is everything. I must have been ready. I took his advice, worked very hard, and got a B.S. and an M.S. in industrial technology in a little over three years.

SAR: When did you start writing?

Mark: Before I got out of high school. Most of what I did was non-fiction, related to building things that I was interested in. My first article dealt with building a muzzle-loading rifle. It was published in a magazine similar to Popular Mechanics, in the late ’50s. I’ve since written hundreds of articles, and three books. I have a driving need to write, to produce.

After college I got a two-year job offer teaching in a state-run vocational school for Natives on Kodiak Island, 100 miles off the coast of Alaska. I went and filled the contract, teaching construction and welding by day, and raising and running a team of Siberian Huskies behind a sled at night. When the teaching contract ended I landed a job in one of our secret satellite facilities, which was primarily involved with monitoring offensive military activities in Soviet Russia. That was the most interesting activity I’ve been involved in. Secret clearance. Important missions. High tech. Crypto. Fascinating, bright people to work with. Remote, secured location. Great food. Very stimulating. I loved it. I’d go back in a minute.

SAR: What then?

Mark: After a time the government contractor who hired me was underbid, and about 300 of us lost our employment. I picked up a job as a welder/fitter/rigger in a ship repair yard. The yard had a 500-ton screw lift, and a set of rails that were used to move vessels around once they were pulled out of the ocean. My favorite job there was running the winch that pulled vessels along the track with a length of 1-1/4-inch cable. Most of the workers were afraid to run the winch, because the cable would frequently jump and make a fearsome noise when it snapped over one of the coils on the drum, and the operator had to stand pretty close, with one hand on the clutch lever. The chances were fair that the operator would get hit and cut in two if the load caught and the cable snapped. I had spent quite a bit of time as a rigger with one of the 40-ton cranes when I worked in the machine shop, so the noise of the cable thrumming and the creaking of the carriages didn’t bother me. I personally inspected the cable and always shackled the carriage myself, so I had faith that the gear wouldn’t fail.

I started teaching writing part-time, at night, for the University of Alaska. They knew I could build and weld, and asked me if I would set up a construction program, and then later a welding program, for their college on Kodiak. I did, and worked in those programs as a college professor for almost twenty years. In the summers I would either fish commercially on my little 45-foot longliner, work in heavy construction, or build rental houses for myself. I ended up with twelve houses in Alaska, and eventually retired from the University in the early ’90s.

SAR: What got you into suppressors?

Mark: I had been interested in the mechanical challenges of sound reduction for some time, and was looking for something to do after retirement. A mutual friend suggested I buy a plane ticket and fly to Fairbanks to spend a couple of days with silencer guru, Al Paulson, who I had met briefly when he worked in Kodiak as a research biologist for the state. I flew up in January, and we spent a couple of days in crisp thirty-degree-below-zero weather firing various silenced machineguns in an abandoned gold mining pit. It’s amazing how few guns actually function effectively in cold weather. The Sterling was the only one that was dependable. It’s also amazing how much energy it takes to stay warm in the interior of Alaska. I spent most of my time on the coast, which is tempered a bit by the ocean, when it isn’t frozen. The interior has a different kind of cold. Al encouraged me to apply for a Class II license, which I did.

SAR: And the rest was easy?

Mark: Not really. I hadn’t run a lathe in almost 30 years. I bought a 1941 South Bend with a locked-up headstock at a military auction and rebuilt it. I was experimenting and manufacturing in my unheated warehouse in the middle of winter in Alaska, going from a macro scale to a micro scale, learning to machine metal all over again, by trial and error. The only benefit from working at ten degrees was that tool bits didn’t often overheat. Forty years ago we ground most of our tool bits by hand. Now we simply change the point on a carbide insert, but one has to know what insert system to base an operation on, and that was an expensive learning process. Shipping, handling and phones to an offshore island in Alaska are very costly. Experimentation and development took up a lot of time. I made a lot of cans that I wasn’t very proud of before I began to understand gas flow and heat dissipation.

Curiously, the same people we’d been spying on 20 years earlier [the Russians] began making regular trips to Kodiak on research and training vessels from Siberia. I made it a point to spend some time with a few of them when they came into town. The Japanese also came, but our cultures were so different that I had a difficult time relating with crews from Japan. The people I got along with best were Russian news crews and former KGB agents. Sometimes I would have dinner with the crew on a Russian vessel. I enjoy cooking for large groups, and I would occasionally organize a dinner party and invite a few of them over to my house. Kodiak is blessed with a great number of people from foreign nations, and I would try to get an interesting mix of people from, say Switzerland, West Germany, Iceland and Israel to combine and have dialogue with the people from the USSR. Most of the Russians could speak fair English, and we often had some very insightful and interesting discussions. I think we changed the way some Soviets think about the United States. It was interesting to walk into an American grocery store with a group of Russians fresh off a boat from Siberia. They couldn’t believe the abundance and variety of goods we had lining the shelves. Yes, the prices were high, but Americans seemed to have plenty of money. They would watch with their mouths open when an American fishing crew came down an aisle with five carts tied together, raking goods off the shelves for a month’s trip, spending $4,000 in an hour.

One of the former agents talked about some S-baffle silencer technology. I took a few simple concepts from what had been orally described to me, and began playing with them, modifying rotation and spacing for various applications. About this same time Ralph Seifert from RASE began calling from Florida, and we began a productive dialogue in experimentation and technology. Ralph is able to take global concepts from many different areas and apply them in novel and interesting ways.

SAR: When and why did you move Sound Technology from Alaska to Alabama?

Mark: I got married a second time, and family pressures (a CFD, or complicated family deal) eventually caused me to move for part of each year. I started to build a shop south of Birmingham in the early ’90s. It took about three more years to scrape up the tooling to duplicate that which I had left in Alaska. I bought new stuff, and developed a manufacturing system that I could be happy with.

SAR: What do you mean by system?

Mark: Whenever anyone assembles a product, there’s a way of cutting out or stamping the pieces, and a method of assembling them. There’s a design philosophy about the product itself. Some manufacture suppressors that are extremely light in weight, are designed to be used a few times on a mission, and then thrown away or destroyed. Some systems work fairly well at first, but then choke up with filth and corruption and won’t ever work effectively again. It’s not hard to design a can that does a good job on a temporary basis, if you don’t care about the longevity of blind alleys and dead ends that won’t clean out unless the unit is disassembled. Many integral systems are built in such a way that all the voids fill up with crud, and the barrel corrodes and seizes to the inside so it can’t ever be taken apart without a hacksaw. While lightweight and small in diameter doesn’t necessarily have to mean fragile and short-lived, that’s often the way it shells out. My life training and work experience in industry and in Alaska has taught me to strive to design ruggedly strong, simple products that can be quickly fabricated and sold for a fair price.

We know that Boeing can make a light, strong, long-lived 737, but a lot of money, material and design expertise will go into a can with those qualities. Imagine what a suppressor a team from Boeing could make if they got funding and set their minds to it.

Most of the aluminum cans that I see are thin and fragile. They don’t have steel inserts where the threads or locking systems wear. The QD systems work fairly well when they are new and freshly greased, but bind up and choke after they are used awhile. I build my stuff to last a long time. Simplicity, strength and longevity are very important to me. If what Sound Tech builds turns out too rugged, too strong, too heavy for you, buy someone else’s can.

SAR: Do you use aluminum?

Mark: While I like aluminum, it has to be used selectively and in a thicker section to handle stress. One can’t normally use thin aluminum for all of the components without having problems with strength and longevity. As a metallurgist, I know that aluminum reaches its maximum strength at a temperature about 200 degrees below zero, F. Aluminum makes a great aircraft structure in the colder temperatures found at forty thousand feet. Steel achieves its maximum strength at about 200+ degrees F, quite near the boiling point of water, and coincidentally the temperature that our .223 M-Cans operate most effectively at. Aluminum softens and begins to sag near 900 degrees, depending on the alloy. That means, when the next blast of gas hits at that temperature, an aluminum baffle has the strength of a warm chocolate chip cookie, and the center will blow out from the impact. I’ve seen this happen to the center of a piston in an outboard engine, and I’ve seen it on suppressor baffles. It’s OK for .22 rimfires and pistol-caliber subguns, but aluminum won’t take the heat blast and powder peaning from high-intensity rifle cartridges. We make 9mm & .223 M16 cans for law enforcement entry teams, and most of them are either all-steel, or have steel shells and end caps. When a team breaks through a door and a member has to physically shove a perp onto the floor with his rifle, the can on the end of that rifle could bend and crush like a cardboard tube if it is thin aluminum. I’m told that a weapon shouldn’t be used like a battering ram, but in the rough-and-tumble atmosphere of a forced entry an officer uses what is in his hand at the time. I believe strongly in short, thick barrels and massive threaded joints.

SAR: Are all your units sealed?

Mark: They are now. We started with cans that came apart, but customers would take them apart and not be able to cram all the pieces back in as tightly as we had. So things would not go, or they would work loose. So now most our cans are steel or stainless, and welded together as a unit.

SAR: Why are they welded?

Mark: Because welding is more efficient, lighter, stronger and more permanent than threading or gluing. You have to remember that I taught welding for over 25 years, and have a lot of experience with industrial metal fabrication. If your only tool is a hammer, all of your solutions will look like nails. My tool is a welder.

Initially I did everything with a stick welder, then invested in a good TIG setup. All the baffles are machined from solid bar stock or heavy steel because I want the holes in the baffles as axially centered as they can be. The extreme geometric shapes I want can’t be achieved with stamped material. I’ve worked very hard to have no dead spots, no closed cells, no areas where crud will be encouraged to build up and pack in, and not have any reason why it won’t wash out with solvent.

The cans are designed to be sealed units, and to be cleaned by immersion in paint thinner or in an ultrasonic cleaner, and then blown out with an air hose. One of my customers had an integral MK II pistol that he stuck a bronze bore brush in, and form-fived it to me for repair after 6,000 rounds. When I finally got it apart the inside was almost perfectly clean. Cans always pack up in the rear first, yet the rear end was very clean. He had been soaking it and blowing it out after every thousand rounds, and this gives me hope that the system is working.

SAR: Do all your customers clean their guns like that?

Mark: Almost no one cleans. They fire their weapons until they absolutely refuse to function. Then they run a can of spray carburetor cleaner at the action to hose it out, hit it with a light touch of Break-Free, and continue on. On a rare occasion someone will take the time to shoot a little carburetor cleaner or light oil into the chamber of the firearm, but that’s about it.

SAR: Does that bother you?

Mark: It’s a fact of life. That’s why I designed the Millennium Can, to be of a large enough volume to handle all that waste and debris, and keep on working.

SAR: The Millennium Can is a big can for a .22 LR. I’ve seen much smaller cans for a .22 that worked.

Mark: But they don’t work nearly as well, nor as long without choking up.

SAR: What inspired you to design the M-Can?

Mark: I kept getting calls from dealers who wanted one can that an entry-level customer could put on both a rifle and a pistol. I resisted for eight years because I refused to turn perfectly good barrels down to thread to a small diameter. I knew that the end result would be a weak joint and a barrel that had lost its accuracy. I would get calls from customers who had had other manufacturers turn and thread their barrels to tiny 3/8 and 1/2-inch stubs, messing up the accuracy. They wanted me to fix mistakes perpetrated by others, and they weren’t fixable because the mistake was in the design of the small diameter, threaded system, which causes the bore to expand at the worst possible place. Eventually I discovered that I could take a heavy barrel and thread the muzzle internally to make a joint between the barrel and can that I could live with. Later I experimented with accurizing concepts and developed the short, thick, ported barrel welded to a short, fat can that we call the MONOLITH. We plotted velocity curves for different barrel lengths to find out just how long a barrel had to be to keep generic ammo subsonic. We experimented with different crowning systems. We played with barrel twists to determine accuracy parameters for bullets of different weights. We developed porting systems to enhance accuracy out of short barrels. I like original research, and enjoy the experimentation involved with making a product more accurate and more dependable. In spite of all that has been written about accuracy, there is no book available that can tell us what we need to know about making a weapon quieter, more accurate and more compact. Much of what we need to know has to come from original research, and it continually surprises me that I learn more by accident than I do on purpose.

Both the M-Can and the Monolith Cans are huge and heavy, but they work on both the 10/22 rifle and the bull-barreled MK II pistol, very effectively. Of course they are obvious, but I’d rather have an honest attempt than something that looked good but wouldn’t perform. I am reminded of the slimline muzzle brakes that are designed to be the same diameter as a barrel’s muzzle. In order to do that the builder has to thread the barrel’s muzzle to a diameter that leaves the wall of the bore almost paper-thin. That makes it fragile, and may also affect accuracy. If they would make the brake larger in diameter it would be more effective, and shorter. It would be an honest attempt, rather than a compromise between effectiveness and disguise. If a customer wants a low profile I’ll be happy to build him an integral MK II pistol with a tube that resembles a bull barrel. More and more of our customers are animal control people, and they need accurate, dependable weapons that can be relied on to do a job. They don’t care what the weapons look like. They don’t want a fine, shiny finish. They just want the weapons to deliver very quiet, accurate, reliable fire when they pick them up off the floor of their pickup.

Our Millennium and Monolith Cans (the Millennium screws on, while the Monolith is welded onto a short, heavy, ported barrel) got excellent sound reductions at the SAR Suppressor Trials. Al Paulson fired a 10/22 with one of our long Monolith Cans and was quite surprised with its level of silence. Out of all the 10/22s he’s ever tested, that was the only one that was so quiet that he could actually hear the recoil spring ringing. After all the heavy construction and chainsaw noise I’ve been exposed to, my hearing is hosed, but others with better hearing tell me they can hear the spring noise, so I believe them.

What most people don’t realize is that .22 ammo is really filthy, and an integral can on a semi-automatic weapon will dump much of that filth into the action. And that action will choke up and fail to function in very short order. The Millennium and Monolith Cans capture most of the crud at the muzzle, so the action stays cleaner longer. And the weight and damping action of almost a pound of metal on the muzzle does wonderful things for accuracy on either a rifle or a pistol.

SAR: Do you have to use subsonic ammo with the M-Can?

Mark: On a pistol with a 5-1/2-inch barrel you really only have about 4-1/2-inches of acceleration, which isn’t enough to get most rimfire bullets supersonic. The Monolith uses a similar short barrel welded to a long can, so most of the ammunition run through it is subsonic as well.

SAR: You work with a lot of different weapons. What are your favorites?

Mark: One of the best designs is the Ruger MK II. It first came on the market 50 years ago and had a few problems, most of which have been worked out. I do hundreds of these a year and I’ve never had one that wouldn’t function easily and well. I like the model with the 5.5-inch bull barrel because it is the most accurate, and because the M-Can interfaces easily with it. I have a customer who likes to shoot rimfire pistols a lot. He’s an excellent shot, and will easily shoot three to five thousand rounds on a weekend. He has owned and worn out over thirty MK IIs. Of all the brands of pistols he’s owned, he says the Ruger MK II stays accurate and functions the best before it finally wears out. He had us build and mount an eight-inch Monolith Can on his newest MK II because he said it was built like a MK II. He is able to easily hit shotgun shells lying in the dirt at 100 yards, offhand, with that pistol.

SAR: Do any other weapons come to mind?

Mark: The Colt 1911 and the M16, both of which have been in U.S. service longer than most other weapons. These are both far more complicated than they need to be, but their modularity make them a joy to work with. Those who are around me a lot will eventually hear me talk about the air-cooled Volkswagen engine being a flawed concept, brilliantly executed. The 1911 and the M16 are similar. They have been around so long and messed with so much that some examples of both are capable of being incredible performers. The locking system, barrel mount, and the straight-line aluminum action of the M16 are brilliant concepts, brilliantly executed. Having the gas tube dump filth into the action is a flaw. When mated with a short, heavy barrel the M16 is far more accurate than it has any right to be. It is very easy to mount a can on, although I prefer to use my own left-hand, large-diameter threads to do that.

SAR: Would you change anything on the M16?

Mark: My ideal weapon would have a short, heavy 16-inch barrel. It would be semi-auto only, have a short, fixed stock and a flat-top receiver to take a 10-power scope with a fat 30mm or 40mm tube. The bayonet mount would go. The weapon would have iron sights that could be deployed as a backup. If the weapon were to be used as a sniper rifle I would mount a seven-inch can on the barrel with heavy, 11/16-inch, left-hand threads to pull it up against a shoulder. If the barrel were thicker I would use even heavier threads. The joint between barrel and can is as critical for accuracy as the joint between receiver and barrel. While I like short, light weapons, I have learned that a stiff barrel is the most accurate. You will note that almost any variation of the M16 one could want is available today, right off a shelf. If I were going to change anything it would be to do something about the gas tube dumping into the action, which is a problem greatly accentuated by a suppressor.

SAR: What are your most popular products?

Mark: The M-Cans outsell everything else we make. They are now made in .22 LR, .223, .308 and 9mm. They are designed to be both effective and economically mass-produced. As a result they are reliable and affordable. The M-Cans and the integral MK IIs are what we do best. They deliver very quiet, very accurate fire at the highest velocity possible. These items constitute about 90% of our sales.

SAR: Why does the M-Can have such rounded ends?

Mark: It’s a small thing, but I’ve always been annoyed with cans that have square corners and razor sharp ends. They’re easy to get cut on, look amateurish, and they resist being shoved into a padded case. When I machine the end caps I cut deep grooves for fillet welds. As the end caps are jigged and welded in place I melt the steel down into those grooves with the tip of a TIG electrode, and then later carefully round off and smooth out the profile in a lathe. Other manufacturers now round off some of their cans in a similar profile, although they still use threaded connections.

SAR: Do you often share ideas with other Class II manufacturers?

Mark: We don’t live in a vacuum. Others in the business have shared some techniques with me, and I have given them some of my ideas. While I don’t bare my soul to everyone, there have been some people in the industry who have helped me, and I don’t mind returning the favor. If a customer calls asking for a can that I don’t make I will refer him to an industry associate who puts out a good product. This is a big field and it’s getting bigger. A little consideration and cooperation go a long way.

SAR: Have you changed the basic design of the M-Can to handle the .223?

Mark: The basic design is similar, except for the use of all-steel components to take the heat. The new .223 M-Can weighs twice as much as the .22 LR M-Can. The 7-inch long .223 can was optimized for roughly 30-grains of gas at a greatly increased pressure level. While a .22 rimfire may uncork as low as 700 psi, the .223 dumps its gas at pressures as great as 10,000 psi, in some situations. We’ve used dedicated rimfire conversion kits in M16s suppressed with our .223 M-Cans, and they work very quietly with subsonic ammo, especially with Aguila’s 60-grain SSS. The reason the non-dedicated units don’t work so well is that the soft lead bullets reach velocities approaching 800 fps before they finally hit the rifling, after being accelerated in the free-bored .223 shell insert. That usually strips the bullets in the rifling, leads the barrels, plugs the gas ports, etc. Very few rifles fitted with those conversion kits are accurate, which is why a dedicated upper unit with a proper chamber is so much more effective.

SAR: Have you had any problems with the .223 can?

Mark: There are two that come to mind, and both are induced by ignorance or carelessness on the part of the shooter. The first has to do with heat buildup. The smaller .223 entry cans are made to go on a short M16 barrel and have minimum bulk. The more effective a can is, the hotter it will get with each shot. On a weapon with an 11.5-inch barrel our little 1.5 by 5-inch cans will increase in temperature considerably every time the piece is discharged. Fire three shots on a warm day and you will burn your hand badly trying to unscrew the can. If someone slams a 100-round Beta C-Mag full of military ball ammo into the weapon and dumps most of it downrange in one continuous burst it will raise the temperature of the can to at least 1,500 degrees F. Since steel becomes plastic shortly after reaching red heat, the primary expansion chamber is going to get hot and bulge under the heat and pressure. Usually one side bulges more, and that will warp the can.

SAR: What happens then?

Mark: If they continue to fire a round could lodge in the can, which usually rips the can from its threads and sends it down range. It happens so fast that an unaware or careless person could ruin both the can and the barrel in seconds. The smaller and more efficient the can is, the greater the problem. And the pressure is on from law enforcement customers to make their cans as compact as possible.

We tell shooters to limit full-auto fire to a single 20-round magazine, but obviously some people just don’t care. We tell them that a meltdown is their responsibility and their problem, not ours. With the use of a machine gun that fires a high-intensity round like the .223, and with a small, highly efficient suppressor, should come the operator knowledge and responsibility to use the weapon with care and moderation. A silencer increases the level of operating pressure, which is capable of boosting the cyclic rate to at least 1,200 rounds per minute under the right conditions. A tremendous amount of damage can be done to both the barrel and the can in as little as 6 seconds. I would prefer it if the fire selector would only allow semi-automatic if a can were installed. In that regard a semi-auto rifle like the AR15 encourages more responsible use than a machine gun like the M16. I have always felt that single, aimed shots are more effective than spray-and-pray, in any event.

SAR: What’s the second problem?

Mark: Water. Every time a weapon is fired water is generated during the combustion process and trapped inside the can. The can has to be unscrewed and allowed to vent after firing or the barrel, the threads (or QD couplings) and the can itself will rust. Cans rusted to barrels are quite common in this business, even with the use of QD couplings and stainless steel. I fired a newly manufactured can just once and then cut it apart to see what the inside looked like. There was no single area that wasn’t totally covered, absolutely saturated with powder residue. Since sulfuric and nitric acids are used in the manufacture of gunpowder, that stuff becomes embedded in every pore of the metal. Add water to that and you will get corrosion. Guaranteed.

SAR: How effective are your .223 cans?

Mark: Initially they were just average, but one of my law enforcement dealers, kept asking me for a more effective can in a smaller package. He had an HK53 (.223) with a 7” barrel that was really vile to shoot. He’d fire a few rounds of military 55-grain ball ammo at a LE demo and the team leader would tell him to put it away. It was that bad. I made a 5-inch long can for that weapon that allowed one to fire it without ear protection. He said “If you can do that for the short-barreled ’53 you need to be making smaller cans for the M16.” So during the week I would make up a few experimental cans with slightly different components and proportions. He would come by on the weekend and we would fire a few rounds through the experimental cans. I would save the best of the lot from that batch and make more like it for the testing the following weekend. I made a lot of unusual experimental stuff that simply wasn’t effective, but eventually developed some features and concepts that were worth concentrating on. The .223 is a very intense, high-pressure round. It responds well to baffles that trap high-pressure gas. It is gratifying to make a 6-inch long .223 can that allows comfortable shooting without ear protection.

SAR: Does the sonic crack of the .223 bullet bother you?

Mark: Any sonic crack is loud, but there’s a way around that. When I built my shop I had the bulldozer operator pile the overburden into a hill. We shoot into that big pile of dirt and clay from about three feet away, and usually there is not enough room for a sonic crack to develop. So we get a pretty good idea of what the can is doing without the distraction of a loud sonic boom. I am told one can shoot a silenced .223 up to 10 feet on some days, under the right atmospheric conditions, and not create a sonic crack. Hit squads have used that phenomenon to good effect for years. We’ve learned quite a little about proportion and baffle spacing from experimental research. We’ve improved the efficiency about 40% over what we used to have, but the changes are primarily subtle changes in proportion — shaving a little off here and adding a little there. I try a lot of concepts that don’t pan out. Occasionally I will gather up a bunch of our newest products and drag them out for testing in front of a number of industry gurus. We feel that every firearm should be suppressed, and strive mightily to do our part.

SAR: Tell us about your 10/22 Pocket Rifle.

Mark: That was a project inspired by a group of federal wildlife control officers who had spent a lot of money on suppressed weapons from another manufacturer. They had cumbersome equipment that was noisy and wasn’t performing for them. One of them had seen my suppressed bullpup prototype at the Atlanta SHOT Show, and asked if it would work for them. I told the group that it wasn’t ready for production yet, but that I would make a short 10/22 that would be accurate, quiet, much cheaper, and almost as compact. This happened about the time that Aguila came out with their 60-grain, subsonic rimfire ammunition. A lot of people were excited about the ammunition, but the bullet was long and wouldn’t group accurately in existing rifles. I had been fooling with fairly expensive, fast-twist barrels and was getting pretty good accuracy out of the SSS ammunition. The fact that this wildlife control was a federal operation meant that they didn’t mind the rifle being a double [tax] stamp gun, since the transfers were free to their institution.

I described the weapon, but they were lukewarm on the project. Once it was built and they actually got to test it, they were very enthusiastic. They couldn’t believe that a short barrel would deliver the power and accuracy required. The long barrel myth has been pounded into us since grade school, and it’s hard for people to believe that firearms have changed that much in the last three hundred years. The first pocket rifle was just thrown together on a pre-ban Choate folding stock, with an old action and a short, lightly ported barrel, with a short, fat Monolith can. The piece was quiet, reliably accurate, and folded into a package about 19-inches long. They used it on deer and feral hogs with good success, as long as their only shots were head shots. The heavy SSS bullet penetrates well, and then bends and turns sideways, so it has good terminal effect without overpenetration. They told me that my rifles were the only weapons that would shoot the SSS accurately, which I attribute to several months of experimentation with different barrels and accurizing techniques. What I learned here would have been useful forty years ago, when they had problems stabilizing M16 rounds in cold climates. It is much more than rifling twist and bullet shape that must be dealt with.

SAR: What is your next book about?

Mark: I’m currently under contract with Paladin for a book on the 10/22 rifle. The book is titled THE ULTIMATE RUGER 10/22 MANUAL AND USER’S GUIDE, and is currently in production.

SAR: Thanks for sharing your thoughts with our readers.

Mark: You are quite welcome.

In the design process for several years, and released just a few short months ago, Ruger’s new, rear-locking bolt gun is a carbine that the class II world has been waiting fifty years for. Very closely proportioned to Ruger’s popular 77/22, the rifle weigh only 6 pounds and is a compact 38 inches long. It has been said that the action is very similar to its little brother, chambered in .22 rimfire.

Background

Before we talk about the 77/44’s potential Class II role, it would be good to discuss the general characteristics of this finely proportioned carbine. In his middle years, Bill Ruger was a sportsman with fond and pleasant memories of time spent afield. As a designer he has an appreciation of small, trim, accurate carbines with enough pep to easily handle medium-sized game. His collective experience of hunting in Africa and America with the semi-auto, 44 Magnum carbine of the 1960s taught him that a 240 grain, .43 caliber slug moving along at a brisk 1,700 fps has penty of penetration and sectional density. It is a round with more lethality than its paper ballistics would seem to indicate.

As we shift forward in time to the 1970s, Ruger’s semi-auto .44 carbine became too costly to produce. It was dropped from production years ago. Shifting forward a little more, a number of atrocities (instigated by gun control zealots and perpetrated by weak-minded individuals who, curiously, seem to have had the same psychologist) have caused a number of countries to either restrict or totally ban semi-automatic (self-loading) firearms. Like it or not (and we really don’t) the day of the manually operated rifle is upon us. Seeing that trend, Sturm, Ruger & Co. is expanding its line of lever and bolt-action rifles with small magazine capacity.

Receiver

The 77/44RS is a traditional rifle with a number of innovative features. The receiver is an investment casting. It is cleverly shaped, machined, surface ground and heat-treated. The versatility of the casting process allows a number of components which have formerly been typically attachments (like the trigger group and scope mounting rail) to be integrally found. While some castings are often bulky, porous and brittle, Ruger’s investment castings tend to be carefully heat treated, strong and ductile. They sometimes allow for a modest amount of weight reduction.

Barrel

The 18-1/2 inch barrel is hammer forged, and it is later turned to finish profile and dimension on a lathe. On the specimens we have examined there is a moderate dovetail slice taken out for the rear sight, a traditional but less than ideal way to mount the sight. In addition to that (and to our great surprise) another rather large dovetail slice has been taken out of the barrel where it is hidden inside the stock. Why this breach of integrity exists remains a mystery to us. If anything is sacred in this world, it is a barrel without dovetail slices and screw penetrations, as these tend to mess up harmonics and spoil inherent accuracy. While on the subject, Ruger has traditionally favored an 18 -1/2 inch carbine barrel for many of their rifles. In this case we feel that a rifled tube, a touch over 16 inches would deliver plenty of velocity, yet will reduce the carbine’s overall length by 2-1/2 inches a worthy goal. The factory barrel has rifling with a full right-hand turn in 20 inches, which is adequate for most .44 Magnum bullets driven to factory velocity. For longer, heavier bullets driven to subsonic velocities, a twist as fast as a turn in 10 inches would provide more stability.

Magazine, Trigger & Safety

The standard 77/44 factory magazine is rotary, removable and holds 4 rounds. It is a very good magazine, feeds well, and I would expect that no trouble will come from it. The trigger is a bit stiff, but that is common and to be expected in this age of litigation. The trigger can be improved by careful stoning and buffing from a competent gunsmith. The lock time is fairly quick, at 3 milliseconds or less. Ruger’s standard bolt safety is proven, convenient and effective. Still, a rule that we lived by in Alaska is to never chamber a round until we were about to shoot. To this day, I will not hunt with a man who carries a round in his rifle’s chamber, and I don’t trust any safety.

Sights & Mounting System

The rifle comes equipped with iron sights which are adequate for young (but not old) eyes. It also comes with a set of low scope rings, which mount in two of three integral depressions molded into the top of the receiver. The factory rings are available for the standard 1-inch tube, and are so low that they only accommodate scopes of fairly low power with small objective lenses. Scopes with a 30mm barrel and/or larger objective lenses will require that another set of rings be ordered at increased cost from the factory. A tough, compact scope of about 4 power would be the appropriate choice for this weapon.

Stock

The standard stock is plain, checkered American black walnut, fitted with a rubber butt pad of medium density. The stock is traditional in appearance, well-formed, properly fitted and quite nice in proportion. It is neither too large nor too small for this trim, handy carbine. As an old stockmaker, I can find no area where material could either be added or removed.

Accuracy

The complete rifle functions quite well for its intended purpose. Most of the specimens we have examined will bench a 3-shot group of 2 to 2-1/2 inches at 100 yards. It must be remembered that this is a carbine, not a sniper rifle. Undoubtedly some rifles will shoot better than this, and some will shoot worse. This is a light rifle intended for carry in a canoe or in the woods.

The .44 Magnum is an adequate 100-yard cartridge. For the handloader, a cast lead, 300-grain, Keith-style bullet has a ballistic coefficient of .213. Starting at a comfortable 1,500 fps, it holds the record for penetration in ballistic gelatin. This bullet will retain a velocity of 1,240 fps at 100 yards, 1,100 fps at 200, 960 fps at 300, 890 fps at 400, and 826 fps at 500 yards. Once reaching subsonic velocity, the flat-nosed bullet loses very little additional velocity. Clearly, the .44 remains lethal at extreme range, but a rainbow-like trajectory makes a first round hit difficult much beyond 100 yards. The bullet will penetrate deeply and effectively at any reasonable range.

Suppressed Use

The first effective suppressed subsonic rifles produced in quantity were the famed British De Lisle carbines of World War II. These were made from reject Enfield rifles, reject .45 ACP submachine gun barrels, and 2-1/4” steel or aluminum tubing. Of varying quality, these rifles quietly drove 230 grain, .45 caliber bullets along at roughly 950 fps. Some were very accurate. Some were not. The most famous use of the De Lisle involved a small contingent of British commandos shooting into a convoy of Japanese soldiers. Shooting from a concealed position on a hillside, the commandos took turns, each shooting a single silenced round at a single soldier in the back of each truck as it drove by. This went on for hours, to the continued amazement of the Brits. For the period, the De Lisles were very effective suppressed carbines. They have been issued and used in many covert and overt engagements since World Ware II, and as recently as the war in the Falklands.

While silencer technology has improved greatly since World War II, the concept of driving a heavy, large caliber slug from a rifle at subsonic speed continues to intrigue. The most recent suitable host rifle has been the Remington 788. Occasionally chambered in .44 Magnum, these rifles were briefly available during the late 1960s, and were then dropped from production. While other repeating rifles have been available, most have tubular magazines that preclude the use of a suppressor. A bolt gun with a magazine beneath the action is the easiest to deal with. Conversions to .44 Magnum, .45 ACP and .45 Colt (the most desirable) have been made from time to time, but these tend to be costly and time consuming to build. They are also plagued with function problems, as they are typically cobbled from something else. Failures to feed, fire and extract are the rule, not the exception. Over the past 60 years a great variety of rifles has been tinkered with and suppressed, with very little success. Until now.

Ruger’s 77/44 finally brings a suppressable bolt-action rifle in a reasonable caliber to the table, where it can be used by police departments, animal control officers, drug interdiction groups, special operations people, and by qualified private citizens.

We recently received a sample of .308 subsonic match cartridges from Engel Ballistic Research Inc., Rt 2, Box 177C, Smithville, TX 78957; Phone 512-360-5327, Fax 2652.

This sample of ammunition is of special interest to us because it comes at a time when very little subsonic ammunition is available in the U.S., and where accusations of inaccuracy and instability are flying between domestic importers of foreign ammunition, and some suppressor manufacturers, each blaming the other for problems their customers may be experiencing.

I covered accuracy and instability in my three-part SAR article on silenced sniper rifles, but would like to mention a few key points again. In .308, one will have the greatest likelihood for dependability and accuracy if: 1) The suppressor is fastened to its barrel with a two-point mount. 2) If the first (and possibly the second) blast baffles is/are symmetrical and axially aligned with the bore. 3) If inherently stable bullets, with round-noses and flat-bases, are used. 4) If the barrel has an adequate twist rate and rifling style for the bullet length and, 5) If the silencers in question have adequate clearance within the cone of dispersion that the departing bullets will describe.

When EBR’s .308 cartridges came in we pulled two rifles from the rack for testing. The first was a standard Remington 700 Varmint rifle with a 1 in 12-inch twist barrel and a synthetic stock. The second rifle was a Savage Tactical with an aftermarket Choate, Ultimate Sniper stock, a 1 in 10-inch twist barrel and an aftermarket, Sharp Shooter trigger.

Velocity testing took place by loading five cartridges in each rifle in an air-conditioned room held at 70 degrees F. The rifles were taken out individually and fired rapidly over a chronograph in 85-degree ambient temperature. The velocities from the Remington were, in order : 991, 1019, 1023, 1032 and 1054 fps. As the weapon’s bore heats up from prior firing, less and less heat is withdrawn from the propellant gas by conduction to the metal in the barrel, thus we expect succeeding shots to be faster and faster as the barrel heats. We see this to a lesser extent in .22 LR firings. The heavier the caliber, the greater the effect, although it seems more accentuated in subsonic loadings than in full-powered loads because there is less gas to work with. The Savage rifle shot its subsonic rounds at 989, 1014, 1031 1056 and 1089 fps, respectively. We expect a little variation in velocity because it is very difficult to get uniform powder measurement and placement in a case that will easily hold 50 grains of powder. We find these velocities to be very consistent and uniform for the low-density, .308 loading.

EBR calls this ammo 7.62mm Thumper, because it uses a heavy, moly-coated, 220 grain round-nosed, flat-based bullet. Slow-fire accuracy testing was conducted under windless conditions the following morning. We had no trouble keeping three-shot groups inside a half-inch at 100-yares, with either rifle. It should be mentioned, however, that the point of impact was roughly 14-inches below, and a bit to one side of our center if aim, as both rifles were sighted in for high-velocity, 158 grain, match ammunition. The difference in pint of impact is due, in part, to different recoil characteristics between the high and low velocity cartridges, and occurs whenever ammunition with substantially different energy levels are used. Both rifles carried heavy, Sound Tech suppressors, which dampened muzzle rise. The sound level appeared to be less when compared with other subsonic ammunition we have tested.

Lighter weight, unsuppressed rifles will be likely to experience a greater degree of apparent drop than 14-inches. If one will be using this ammunition for serious work we recommend sighting the weapon in to accommodate subsonic trajectory and rotation, at a range at which firing is anticipated. It is very difficult to remember the zero for different rounds. Not impossible, but difficult. We also suggest using Thumper ammunition exclusively, rather than mixing ammo types. Round-nosed bullets with flat bases are dependably stable, inherently accurate, and usually penetrate in a straight line. Do not expect subsonic ammunition to be noiseless in an unsuppressed weapon. The report will be substantial unless a suppressor is involved.

The 220 grain, moly-coated bullet should deliver about 484 foot pounds of energy at 1000 fps. While the suppressed report was mild, we noticed both rifles recoiling about three inches, judging by the skid marks generated by the bipod on the shooting bench. It is apparent that 220 grains of lead and copper are traveling down range each time the trigger is pulled.

We pulled a bullet from one of the cartridges and got about 12.7 grains of a coarse, light, tubular powder, of a type that we are unfamiliar with. In all of the EBR testing we conducted, none of the subsonic bullets broke the sound barrier. This is significant, as other samples of subsonic rounds furnished us by other manufacturers frequently broke the sound barrier. This is supposed to be stealthy stuff, and it won’t be stealthy if it goes beyond the speed of sound.

Engel Ballistic Research is currently at work on a heavy, .30 caliber rifle round that purportedly will expand reliably and effectively at velocities below 1000 fps. To date, we have not seen a rifle bullet capable of doing this, and we look forward to testing this round in the future.

The Use of Sound Suppressors on High-Powered Rifles

This article will deal with choosing, loading and using accurate subsonic rifles. Unlike the more powerful supersonic rifles, whose bullets generate their own supersonic crack, subsonic rifles are capable of delivering very quiet, almost undetectable, accurate fire. The sound of a subsonic bullet whizzing through the air at 1,000 fps is very quiet indeed, certainly less than an arrow from a bow at 200 fps. We won’t get heavily into the science of it, but a velocity of 1,000 fps (or roughly 300 meters per second) has long been considered optimal, since well before World War II. Any slower, and we’re leaving precious velocity on the table. Any faster, and one runs the risk of breaking into the sound barrier (1,100 fps) in a hot environment, where gunpowder burns more effectively. A warm barrel or a hot cartridge can easily push velocity up another 150 fps, even though the cartridge contains a bullet of the same weight and powder charge.

With a properly designed system, the loudest sound will be that of the bullet strike. With effective suppressor technology we can all but eliminate the sound of a muzzle blast. By hovering around 1,000 fps we can virtually eliminate bullet flight noise. The only thing left is the plop of bullet impact, which can be quite loud on occasion.

Power Level

Subsonic bullets travel much slower than high-powered rifle bullets. Since the formula for energy squares velocity, it can be seen that the subsonic bullet must try to make up for the loss of power with mass, clever bullet design and accurate shot placement.

One standard formula divides velocity squared by a factor of 450,400. That, times the bullet weight in grains, will equal energy in foot pounds. Let’s take a 200 grain, .308 bullet and crunch some numbers. At 2,400 fps that bullet will deliver 2,558 foot pounds of energy. At 1,000 fps the same slug will only deliver 444 foot pounds of energy.

A 300 grain, .44 Magnum bullet driven at 1,000 fps will delivery 666 foot pounds of energy. A 55 grain, .223 bullet will develop 1,250 foot pounds of energy at 3,200 fps. While the energy of a .223 on paper may be twice that of the .44 Magnum, the 44’s greater mass and deeper penetration will prove far more deadly on large animals. In the 1960s the friends and family of the Ruger empire spent quite a bit of time in Africa with their .44 Magnum, semi-auto carbines. Most who used those .44 carbines were very impressed with their lethality. The .44 is a lot more effective than the paper ballistics would lead one to believe.

For those who enjoy playing with calculators, a factor of 2.22, times the proposed bullet weight in grains, will equal foot pounds of energy at a velocity of 1,000 fps.

Barrel Length and Porting

One doesn’t need much barrel length to develop a minimal 1,000 fps of velocity with a heavy, large caliber bullet. An 8 to 10 inch tube will provide plenty of acceleration. For the record, a good 10 inch barrel is fully as accurate as a much longer one. One more time, with feeling, a 10 inch barrel is fully as accurate as a 30 inch barrel. We often note a significant increase in accuracy when we cut a 24 inch barrel back to 10 inches. A proper chamber, adequate rifling twist rate and a perfect muzzle crown are all more important than barrel length.

If porting (holes drilled in the barrel to bleed propellant gas) is used as one of the devices to reduce the noise of a suppressed firearm, it is recommended that the barrel be from 10 to 12 inches in length. Porting, when properly executed, can reduce a suppressor’s overall report by as much as 40%. All ports should carry a substantial 45 degree bevel at the bore interface, or they will shave off copper or lead from the bullets, which will pack up the primary expansion chamber and the ports themselves. If a suppressor eventually weighs 8 pounds more than it used to, there is a good chance that sharp or burred ports are at fault. Many manufacturers bevel the outside of each port, but this does little or nothing to cure the problem. Beveling the inside of each port is not easy, but it must be done.

For private ownership in the U.S., a pistol barrel may be of any length. A rifle barrel must be over 16 inches long. Any shorter, and a $200 Federal tax stamp (and a Form 4) will be due on private ownership. Municipality, county or state ownership of a short barreled rifle or suppressor will of course require federal registration, but no tax stamp will be due.

Caliber Selection and Bullet Shape

Since velocity is rigidly fixed, the most important area of the selection process will be based on the assigned role of the firearm. Plinkers and target shooters are well served with the common .22 LR round. It’s cheap, quiet, available and accurate. The high-speed .22 LR round is transonic, which means that it starts out faster than 1,100 fps (supersonic) but then its velocity decays into the area where parts of the bullet are supersonic, and parts are not. When a bullet travels through the transonic range the frictional pull trying to slow it down is from four to five times greater than the pull that exists at subsonic velocity. Simply put, this differential pull causes instability. A stable, round-nosed, flat-based bullet (like the .22 LR) will be less accurate in the transonic range. Inherently unstable, hollow-point, boat-tailed bullets (with the preponderance of mass to the rear) will lose all stability in the transonic range, tumbling end-over-end and losing any semblance of accuracy at that speed. Thirty years ago, those who drove Chrysler vehicles on slippery roads in the northern states found that, in a situation where control was lost, the vehicle would spin and settle into a rear end-first attitude, because the rear end was heavier than the front end. Those who drove Ford products (which typically had less rear-wheel traction on ice) soon learned that the heavier front end caused the vehicle to be more stable in a spin. Its natural movement in a minimal traction situation was front-end first. Sharply pointed bullets have the heaviest end at the rear, and they take a much greater spin rate to keep them pointed in the right direction. Bullets with blunt points and hollow bases (Like hollow-based, wadcutters) are inherently stable in flight. They fly straight, even without spin.

In terms of effectiveness on live targets, it is very hard to beat a blunt-nosed or flat-tipped bullet. Put another way, a subsonic bullet that is a true cylinder will deliver more shock, hemorrhage and trauma than any other shape. Sharply pointed and round-nosed projectiles will slip right through, while causing minimal damage. It has been said that some .30 caliber projectiles are designed to expand at 1,000 fps, but this remains to be proven to my satisfaction. Sharply pointed bullets will penetrate deeply at subsonic velocities – pushing nerve tissue and blood vessels aside, rather than cutting them. Unless the bullet hits the base of the brain or a major nerve center, the animal will run away, usually to die a slow and agonizing death. Most pointed and round-nosed .30 caliber rifle bullets are totally lacking in knockdown power at subsonic velocities. We hear the same stories of subsonic .30 caliber bullet inadequacies over and over again, and are frankly quite tired of them. Subsonic .30 caliber bullets will not expand in large animals. The only effective .30 caliber subsonic bullet will have a totally flat front end.

For those entities involved with animal control, the subsonic .22 LR round is relatively humane (meaning it kills quickly) and effective on animals weighing up to roughly 20 pounds. On snakes and small vermin the Remington Subsonic, hollow-point round is fairly effective. It usually stays subsonic, even in long, unported barrels, and is fairly accurate. On very small rodents a round called the .22 CB Long offers reduced bullet weight and less penetration. It is not a very accurate round, but works OK for squirrels in attics and pigeons inside barns at close range. It will sometimes penetrate a sheet metal roof, so one must be careful regarding a backstop. On larger, tougher animals CCI’s SGB (small game bullet) offers extreme accuracy and deep, effective penetration. Unlike high-velocity hollowpoints, which often fragment and perform poorly, the SGB is one of the first modern attempts at scientific design in a rimfire cartridge. Its bullet is of hardened lead, with a solid, but slightly flattened tip. If I were going to pack a small .22 rifle into a wilderness survival kit, it would be accompanied by a large supply of SGBs. They work well on small animals, and work better than any other .22 LR round on larger animals. Until someone comes up with a .22 LR wadcutter (I hope CCI is listening) the SGB will remain the most effective .22 rimfire round available.

The next stop up the ladder of higher subsonic energy is the move to a .30 caliber weapon. The .308 is a logical place to start, and (with a light charge of fast powder) it can be effective in a weapon that is designed to be both subsonic and supersonic. A 1 in 10 inch twist will stabilize up to a 200 grain, round-nosed, flat-based bullet. However, the extra room in the .308 case provides a substantial cushion, which can cause problems with efficiency and consistency. The most ideal situation results when a cartridge case is just big enough to hold its charge of powder and a bullet, with no room to spare. In the 60s a fellow named Joe Apache necked a .223 case up to .30 caliber. The result was an interesting cartridge called the .30 Apache, which sat ignored for quite a number of years.

Eventually the use of suppressors burgeoned in the U.S. and Grendel Arms (now known as Keltec) began experimenting with a similar case in a suppressed M16. The concept eventually developed into what is now known as the .300 Whisper. That small .30 caliber cartridge will easily launch a bullet as heavy as 250 grains at a subsonic velocity. Not surprisingly, the longer, heavier bullets have to be spun at a full turn in 6 to 8 inches in order to stabilize at low velocity. Again, it has been said that some of these heavy bullets will expand at subsonic velocity, but I’ve seen absolutely no evidence of it. Indeed, they usually perform like a knitting needle, poking a small, straight hole, in one side and out the other, wasting 90 percent of their limited energy beyond the primary target. I’ve heard the word tumble used in conjunction with the .300 Whisper, but I’ve not seen that happen either. The heavy bullets are capable of extreme penetration, but I have seen absolutely no inclination towards tumbling. Many have had great expectations for the subsonic Whisper cartridge, but until they develop a flat point for a hard, .30 caliber bullet, I feel that they will continue to be disappointed.

Dr. Martin Fackler, founder of International Wound Ballistics Association, devoted a considerable amount of research, study and experimentation to the subject of subsonic bullets. Based on his own and other research going back 200 years, Dr. Fackler (in a nutshell) concluded that hollowpoints and expanding bullets are a waste of effort. One can do no better than to use a simple, hard-cast lead bullet with a totally flat nose, and with sharp edges at the transition between the flat face and the cylinder walls. Such a bullet does not move through the air with the extreme ease of a VLD (very low drag) bullet, but its terminal effect is considerable.

The next logical step up in caliber is to .338. In the early 70s, Max Atchisson of Georgia cut off the shoulder of a .223 case and trimmed it to an overall length of 1.412 inches. The result was a case mouth of the perfect size for a .338 bullet. Called the .338-223 Straight, the cartridge is of great interest. Like the .300 Whisper, it will launch a heavy bullet very quietly. I am told that either of these efficient bullets will arrive at a target 300 yards distant with a loss of less than 100 fps. Those who are used to supersonic bullets will find this astounding, but one must remember that it takes a lot of energy to break the sound barrier on a continuous basis. A subsonic bullet that isn’t wobbling in flight is the Honda Civic of the firearms world. It moves through the air with a velocity decay rate roughly one-fourth the rate of a supersonic bullet. Until we get a flat-nosed .338 bullet, this cartridge will also suffer from the same knitting needle-like effect.

We could stop to visit with the .38, but I’m going to bypass that and settle on the .44, which is really .43 (actually .429) caliber. Ruger now makes a lever-action and a bolt-action rifle, both of which are chambered in the powerful .44 Magnum cartridge. We’ve been waiting for twenty years for these rifles, and are immensely pleased that they are finally on the market. Wadcutters and flat-nosed, cast bullets are available in weights from 185 to 300 grains. For those who hand cast, the weights range from 80 to 362 grains. Since factory ammunition is usually too fast, the subsonic .44 Magnum rifle is a handloading proposition. Fortunately, Mike Dillon’s Square Deal press is affordable, and cranks satisfactory rounds out at a prodigious rate. The twist in Ruger’s .44 barrel is 1 turn in 20 inches, which seems to stabilize 300 grain bullets effectively. It should be mentioned that, while barrel leading can be a problem with lead bullets driven beyond 1,400 fps, it will not be a problem with lubricated, hard-cast bullets driven to 1,000 fps. We should also mention that we’ve been buying plain-based, hard-cast, lubricated lead bullets from Brownells, and that we shoot them backwards in order to get the maximum effect. Midway, Dillon and quite a number of other suppliers sell swaged or cast lead, lubricated bullets for both the .44 and the .45. We don’t care about ballistic coefficient nearly as much as we care about terminal performance, which has been rated as nothing short of excellent by contractors, animal control officers and park rangers. The flat-nosed .44 delivers a mighty whack. It has excellent knockdown power. It isn’t a good 300 yard weapon, but remember, we’re talking subsonic here. Any bullet that moves at a sedate 1,000 fps will have a rainbow-like trajectory much beyond 100 yards. Little velocity is lost, and the weapon is still very accurate at extreme range, but finding the proper elevation adjustment can be tricky.

The powders of choice have been the time-honored Unique and a powder made in Finland by Vihta Vuori Oy called N 310. The Germans developed a very fast powder for their suppressed rifles during World War II, and this may be a very close duplicate of that powder. It should be mentioned that the Finns turned some of their subsonic rifle bullets backwards for better accuracy and improved terminal performance. They also developed a system using a few drops of solvent to dissolve the upper layer of their fast powder. After this solvent evaporated, the powder was thus sealed into the rear of large-volume cartridge cases. A bullet was then seated and heavily crimped in place. This helped to achieve better combustion and improved uniformity. Prior to this a filler, such as nitrated cotton fiber or kapok, had been used on large-volume shells. The solvent was a stroke of genius because it rapidly evaporated, did the job very effectively, and left nothing extra inside their suppressors.

Interestingly, we were using N 310 powder in a Thompson Contender, which developed the disconcerting habit of opening up by itself each time it was fired. Curiously, no damage occurred, and the bullets hit the target as though nothing was amiss. The standard pistol primers did not indicate any sign of high pressure. The velocity was 1,000 fps, out of a 21 inch, unported barrel. After this happened several times in a row we switched to Unique (a slower powder) and the problem went away.

H & R and NEF also make a single-shot, break-open carbine, chambered in either .44 Magnum or .45-70. These rifles are more robust than the Thompson Contender, and remain closed when fired, regardless of the load. At a mere $150, these are the cheapest games in town. Don’t think that inexpensive means unreliable or inaccurate. These are very reliable, accurate weapons. More so than the expensive and finicky Contender.

Dating back to 1873, the .45 Colt is a close cousin to the .44. This rimmed cartridge offers 10% greater frontal area. The caliber and the cartridge were the end product of a lot of cut-and-try research. The .45 Colt may be old, but it certainly isn’t obsolete. Many who hunt deer with a revolver feel that the .45 Colt is as close to perfection as one can get. We really like the cartridge, but are having a hard time finding rifles we like with the .45 Colt chambering. Winchester and Marlin both make lever-action rifles, but the feed tube is tied to the barrel and gets in the way of the suppressor. We’ve been buying .45 Colt barrels with a 1 in 14 inch twist from Bullberry in Utah for the single shot, Thompson Contender. We look forward to the day when H & R, RUGER and NEF make their rifles in .45 Colt.

The .45-70 cartridge seems like an obvious step beyond the .45 Colt. We’ve suppressed this round but are not as happy with it as we are with the .45 Colt. The Colt has a slug with a .451 inch diameter and is available with bullet weights up to 425 grains. As a cartridge, the Colt is compact and easily loaded. Its case walls are heavy and durable. The current popularity of cowboy action shooting make the .45 Colt cartridges readily available, and inexpensive. The .45-70 has a bit more capacity than we really like, and its case walls are quite thin near the mouth. The mouth is easily bent or deformed. We’ve crumpled and ruined quite a number of .45-70 cases while attempting to resize or seat bullets. The diameter of the .45-70 is .458 inches. Cast bullets are available in weights up to 645 grains, which ought to be plenty for almost any situation we can envision in North America.

Some have attempted to suppress the mighty .458 Winchester Magnum. That is truly a waste of effort, as there is absolutely no difference between the subsonic .458 and the subsonic .45-70, other than that the .45-70 is more efficient because its case capacity is smaller. We’re not saying no to either the .45-70 or the .458, it’s just that we like the .45 Colt a lot more. The .44 Magnum and the .45 Colt suppressed rifles are perfectly suited to the task of quietly harvesting or removing animals weighing between 100 and 600 pounds. Both cartridges are supremely accurate and very efficient at subsonic velocities. The ideal weight of bullet will drive completely through the animal in questions, remaining just under the skin on the far side. This is a close to perfection as it gets. The .44 Magnum and the .45 Colt have excellent knockdown power when loaded with bullets having absolutely flat front ends.

The only possible improvement over the .44 and the .45 Colt would be a move to the legal maximum diameter in the U.S., which would be .50 caliber. Interestingly, the French were among the first to do this in the 1870s, when they fitted one of the first metallic silencers to a .50 caliber Remington Rolling Block pistol. The.50 Remington (M71 Army) used blackpowder to drive a 300 grain lead bullet along at a sedate 600 fps. The powder was corrosive, and the suppressor would have to be boiled out with soap and water, and then oiled after use, or it would eventually be destroyed by corrosion. Rimmed .50 caliber cartridges can be made from 50-70 brass, an expensive and laborious tasks. A wadcutter bullet would have to be designed in .50 as this is not an item which is readily available. The .50 caliber offers almost 20% greater frontal area over the .45. A bullet weighing between 400 and 1,000 grains would seem appropriate for this caliber. Again, we have been very happy with the .44 and the .45 Colt, and find a need for anything beyond these two cartridges unlikely.

Suppliers

Brownells, Inc., 200 S. Front St., Montezuma, Iowa 50171. Phone: 515-623-5401, Fax 515-623-3896

Bullberry, 2430 W. 230 N. 67-5 Hurrican, Utah 84737. Phone: 801-635-9866

Dillon Precision Products, 8009 E. Dillon’s Way, Scottsdale, AZ 85260-9865 Phone: 800-223-4570, Fax 602-998-2786

Midway, Box 718, Columbia, MO 65205. Phone: 800-243-3220, Fax 573-446-1018

NEI Handtools, a supplier of custom bullet molds, 51583 Columbia River Highway, Scappoose, OR 97056. Phone: 503-543-6776, Fax 7865

Barrel Length and Overall Rifle Length

Most sniper rifles have barrels ranging from 24 to 30 inches in length. An effective suppressor needs from 8 to 12 inches of length in front of the muzzle in order to function properly. A 4 foot long rifle can easily become a 5 foot long rifle with the addition of a muzzle can, and this may be awkward in some situations. Most suppressed rifles have fairly short barrels in order to reduce the overall length. Expect to lose about 140 fps when cutting a 26 inch, .308 barrel down to 20 inches. As a practical matter, most high-powered rifle barrels are cut to between 16 and 18 inches. We have been taught from grade school that long barrels are much more accurate than short barrels, but this has no basis in fact. We personally find that an 18 inch barrel is a bit more accurate than a 26 inch barrel. The chamber, throat, crown and rifling are more important than barrel length. Subsonic rifle barrels may range from 8 to 12 inches in length. One does not need very much linear acceleration in order to reach a velocity of 1,000 fps with a .308 bullet. Privately owned rifles in the U.S. must have barrels over 16 inches in length, or they will require a $200 Federal Tax Stamp and registration in order to remain legal. A steel suppressor tube can be welded to a short barrel to avoid the tax and the hassle, as long as the overall length of the unit is beyond 16 inches. Soft solder or glue is not an acceptable alternative to welding. The intent of the BATF ruling is that the assembly must be permanent, and not easily altered. To clear up confusion, shotgun barrels must be over 18 inches in length. Again, rifle barrels must be over 16 inches long. This is of no concern to police and military where the organization or unit (not the individual) actually owns the weapons, although LE agencies are still required to register these with ATF.

If you have a choice of bullet weight it is useful to know that heavier bullets operate more efficiently (than light bullets) out of a short barrel. A .223 barrel should have a 1 in 7 inch twist in order to stabilize the heavier 69 and 80 grain bullets. A .308 barrel (shooting 180 and 200 grain bullets) is best served with a 1 in 10 inch twist. The common 1 in 12 and 1 in 14 inch .308 twists won’t stabilize any .308 bullet much heavier than the industry standard 168 grain, boat-tailed, hollow point, match projectile. If stability is a problem, round-nosed, flat-based bullets may be the answer. They are inherently more stable than sharply pointed, boat-tailed projectiles.

Subsonic bullets are not normally shot in combination with high-powered bullets. Because of softer recoil characteristics and less muzzle rise, a subsonic .308 can be expected to strike roughly 14 inches lower than a full-powered load at 100 yards. Again, the issues of cold shot zero and liability raise their ugly heads. During WW II, subsonic rifle bullets were sometimes loaded and fired backwards in suppressed rifles. This resulted in an increase in both accuracy and terminal effectiveness.
Tactical users who must use factory ammunition will be best served with the 168 grain, Limited Penetration (LP) round from Black Hills, unless they are shooting through steel or glass. The LP round duplicates other match rounds in accuracy and zero, but is designed to virtually explode upon impact, leaving no large fragments to exit the primary target and cause secondary injury to other individuals. A standard .308, 168 grain, match round has proven itself capable of penetrating over 40 layers of 1/2 inch sheetrock after exiting a primary target, a serious legal liability in the law-enforcement arena.

Suppressor Length, Volume and Profile

Design excellence aside, bigger is usually more effective. Volume can be achieved more effectively with diameter rather than length, but both are important. High-powered rifles require an exterior diameter of at least 1-1/2 inches, and a length in front of the muzzle of at least 7 to 10 inches. Subsonic rifles often require maximum suppression. Without a sonic boom it is possible to totally mask an event such as a gunshot. Since high-powered projectiles will always generate their own noise, there is little point in trying for extreme suppression. A good suppressor exists to make shooting comfortable without hearing protection, and to mask the location of the shooter. Greatly reduced recoil and an increase in practical accuracy are side benefits.

Public Relations

The traditional visual profile of a muzzle can carries a public relations stigma that goes back to 1934, and is not easily overcome. It is possible to disguise the profile of a slender muzzle can by extending the tube all the way back to the receiver. On a high-powered rifle this adds weight and expensive stock work. To some, the penalty of money and weight is worth the effort. The diameter of a Remington or Savage action is 1-3/8 inch, which seems to be the inside limit for a rifle suppressor. We had such a suppressor built (1-3/8 in diameter by 24 inches long) on a Savage .223 varmint rifle with a laminated wood stock. The disguise was extremely effective. A public relations stigma did not follow this weapon. We took it to firing ranges and gun shows and brandished it in public. Unlike the typical rifle with a muzzle can, no one appeared alarmed by its presence. Experts refused to believe it was anything but a bull-barreled target rifle, even after being told that it was suppressed. Unfortunately, the slim tube (extending a mere 8 inches in front of the muzzle) did not have the suppression rate that a normal 1 1/2 by 12 inch tube would have provided. A larger diameter action would allow a larger diameter tube to be installed without looking unusual. These actions are available, but they are more expensive. It is possible to have the tube larger in diameter than the action, but this looks unusual, thus the disguise is not as effective.

Gunfire noise is the most objectionable sound to the public at large. The louder it is, the more of a problem it creates in an urban area. A quieter sound is perceived as less lethal, and is therefore less objectionable. Where rifle fire must be used in an urban setting by law-enforcement personnel, a suppressor will greatly reduce the PR fallout, as long as it remains shielded from public view.

Heat Buildup

Typically, the hotter the suppressor gets with a single shot, the more effective it is. Full-auto fire with a suppressor will dramatically increase cyclic rate. It will also raise barrel temperatures considerably, because the hot gasses are trapped inside for a longer period of time. Full-auto fire is best kept to two or three-shot bursts. As a general rule we don’t expect machine guns to be very effective in a tactical scenario. Most perps will be behind cover by the third round. We are much more in favor of a single, carefully directed shot. We believe that accurate, effective, long distance tactical fire is more likely to occur with a bolt action rifle than with a bullet hose. The commotion associated with most machine guns is much more likely to draw attention than a single rifle shot, whether the firearms are suppressed or not.

Suppressor Construction

The metals most commonly encountered in suppressors are chrome moly (usually 4130) steel, stainless steels, aluminum and titanium. Chrome moly steel is hard, tough and very durable. It takes non-reflective surfaces (Parkerizing) and holds paint very well. Paint is fast becoming the coating of choice, as it is corrosion-resistant, and can be changed (to camo) or easily renewed as situations warrant. Bake-on polymers can be cured in an oven at 350 degrees F. Some of these coatings are very tough indeed, and serve well in extended firings.

Aluminum is light in weight (about a third the weight of steel) but it is fragile and doesn’t take knocks, abuse and thread wear very well. Nor does it take heat well. It gets very soft and then fails and melts near 900 degrees F. By contrast, steel won’t melt until it reaches 2,700 degrees F.

Some aluminum cans are anodized, and then dyed black. The anodized coating looks good at first, but then gets beat-up and chipped. Aluminum does not take or hold paint very well, even after being sand blasted. Aluminum has a very high heat conductivity. This is a good property, because it will allow the material to rapidly absorb heat from the burned propellant gasses, reducing noise in the process. There is an old saying in the suppressor industry: “Put the fire out quickly, cool the gasses down.” Most aluminum is 6061-T6, which is much cheaper than steel, and moderately easy to machine, although it is sticky and tends to gall. End caps and baffles are usually machined out of 2024, which is soft and very easily cut. The alloy 7075 is sometimes used. It is hard, strong, more expensive, and abrasive to cut. Most aluminum will bend considerably before it finally breaks. The alloy 7075 cracks before it gives, and is not weldable. The alloys 6061 and 2024 are weldable, but most aluminum cans are threaded and glued together. When an aluminum can fails it usually does so at the root of a threaded joint, at the blast area.

The softness of aluminum makes it very prone to wear at contact points, such as the threaded joint where it is screwed or locked on to a barrel. Gas erosion can be severe in a high-powered rifle. Aluminum also has a high co-efficient of expansion, and this can cause problems with zero, or with a rapid loosening of parts. It is so soft that axial alignment may eventually become a problem as threads get beaten loose and sloppy. Cast aluminum is very porous and weak, and should not be used.

Stainless steel has nickel and chrome alloyed in with the steel. It is more corrosion resistant than steel or aluminum. Stainless holds paint poorly, and also has a high coefficient of expansion. Stainless comes in many grades and hardnesses. The harder grades can be brittle. The softer grades are subject to thread wear and deformation from battering. Stainless is expensive and hard to machine. It is not available in the variety of sizes that one finds with aluminum and steel. Stainless has a fair degree of conductivity. It is not as reliable as steel. When a stainless can fails it usually does so along a seam, or at the root of a threaded joint in the blast area.

The commonly used type 304L series of stainless is dead soft, very corrosion resistant, easy to machine and welds beautifully. Its downfall is that it is easily deformed. If a can made of 304L is dropped or impacted in shipping or deployment it may easily be deformed, and this may affect axial alignment. Other commonly used stainless alloys, such as 316 and 321 tend to be harder and more resilient, but they are also much more difficult to machine and weld. There are literally hundreds of stainless alloys available, and they may have very different characteristics. Those used for some rifle barrels have high percentages of sulfur and lead, which improves machinability while decreasing wearability. The ideal stainless alloy would posses the ductility, machinability, resilience and weldability of 4130, chrome moly steel, yet be susceptible to corrosion.

Titanium is about half the weight of steel, has a very poor conductivity, is very expensive, is highly resistant to corrosion, and is almost as strong as steel. It is very difficult to machine. It destroys cutting tools because its abrasive nature combines with its poor conductivity to produce high heat buildup in cutting tools, softening their edges. Titanium takes and holds paint fairly well. It is about as shiny as stainless, but is a little darker in color. Titanium’s light weight and strength are a plus. Extremely high cost and poor conductivity are a minus. There are several titanium alloys available, the most common of which is 3, 2.5 (pronounced three two five), containing 3 % aluminum, 2 1/2 % vanadium, and 94 1/2 % titanium, which is used in high-end bicycle frames. The alloy 6A4V90T is sometimes used in receivers and barrels. The bore life of a titanium barrel is not especially good.

Steel, stainless steel and titanium are very weldable using the TIG (tungsten, inert gas) process. Aluminum is also weldable, but it takes a high degree of skill and experience to do so effectively. Only steel and stainless steel are able to be welded to each other in a meaningful way.

Threading and Alignment

Suppressor manufacturers fall into two camps – Threaders and Welders. Neither likes the other, and both think that their own methods are vastly superior. Threading greatly weakens the tube. Welding is strong and permanent, but distorts the metal. Just as there is a constant and vigorous search for better and more complex baffles, so too does the controversy between welders and threaders rage.

There is usually a demand for a wide variety of suppressors, so individual manufacturers stock a variety of parts for different models, most of which have been turned out on CNC or automatic screw machines, in limited runs. The parts are kept in bins, and usually consist of a main tube or body (which is the registered, serially numbered part in the U.S.), a front end cap, a rear end cap, and a baffle stack – which may or may not be sequentially important. If the baffle stack is sequential the larger spaces are usually towards the rear, near the barrel’s muzzle, while the smaller spaces are probably in the front. So many cans have been taken apart by incompetents, and reassembled incorrectly, that the industry trend has been towards sealed units that can be cleaned by immersion in a solvent. Design rip-offs are common in the industry, thus welding and sealants are also used to mitigate intellectual thievery. Baffle design, optimal spacing and proportion are critical to performance. Patents abound, but they afford little protection in foreign countries. Often, patent drawings do nothing more than afford competitors baffle designs that they would otherwise have to purchase and destroy suppressors in order to obtain.

A can with a single-point mount relies on the rear end cap for all of its axial and angular alignment. The rear end cap was probably made on an automatic screw machine, and bored and threaded to take a barrel at the same time. It is critical to the alignment procedure that this was done with extreme accuracy, as a tiny amount of angular or axial misalignment can result in severe misalignment (and possible baffle contact) in a 10 inch long can. The best way to bore and thread a rear end cap is to screw and glue (or weld) it into its suppressor tube first, and then place the entire unit in a lathe for the remainder of the machining. Few bother to do this, however, because it is much easier to take finished parts out of bins and assemble them. Line boring and threading in a lathe might mean having to refinish already completed parts. We have seen a 7 inch long can from a prominent manufacturer that had 3 degrees of angular misalignment after it was mounted on its dedicated barrel. This may not sound like much, but try to remember the sometimes-close tolerances between bullet path and baffles.

If the rear end cap had been welded instead of threaded on, the chances are better that the unit had been bored and threaded on a lathe after assembly. Welding induces distortion as the liquid metal cools, solidifies and shrinks, so it is nearly impossible to successfully thread the bore of a rear end cap before welding. Almost all of the angular and axial alignment problems we see today are related to a single-point mount on a rear end cap that has been improperly machined prior to being assembled. Again, tubes that have threaded rear end caps are prone to fatigue and a possible massive failure at the root of the last inside thread, at the blast chamber. Pressure is low near the front of the can; thus we rarely see a failure at this point, unless there is baffle contact and bullet tumbling.

Most two-point mounts have the threaded portion (commonly called “the nut” or “the spider”) located in a more central portion of the suppressor tube. This threaded portion is very important, as it holds the entire can in place – usually by pulling it tightly against the rear end cap. There are many methods of holding the nut in place, and none of them are without their problems: A snap ring may be inserted in a groove in the center of the tube, but this groove weakens the tube near the blast chamber. The nut must also be pinned in place, or it will rotate. The nut can be plug-welded through holes drilled in the tube, but the welding process slightly distorts (bends) the tube, even if 4 or 6 welds are placed in direct opposition to each other. The welded or threaded rear end cap can push a thin section of tubing against the nut, but that nut must still be pinned or glued in place or it will rotate. Lastly, the nut can be silver soldered or brazed in place, but the area is tough to see through smoke and fume inside the tube, hence it is difficult to be sure that a proper bond has been achieved. The soldering process may distort the tube. One must be careful to boil out the tube in water afterwards, to remove corrosive salts left by the soldering flux.

The barrel which mates to a suppressor must be turned in a lathe. Threads are best turned with a cutting tool as the barrel rotates between centers, but I have also seen satisfactory results obtained with a die-holding fixture in a carriage or tailstock. Machine threading on a lathe with a single point cutting tool is often called single pointing, which is not to be confused with a single-point mount. It is felt in the industry that single point threads are the most accurate. Rolled threads are the strongest, as they are forged during the process of rolling between two dies.

Few barrels are either straight or symmetrical, and this is another possible source for angular or axial misalignment. A practiced eye can spot a barrel with a crooked bore. If the muzzle is clear and open, one can peer down the headstock as the barrel spins in a lathe to get a good idea about how true the bore is. Short, thick barrels are easier to deal with than long, thin ones. Barrels which are fluted are often bent during the fluting process if they are not properly supported and frequently rotated. Fluting has ruined many otherwise perfectly good barrels. Most fluting is purely decorative in nature, and normally performs no useful function; no matter what manufacturers claims are made to the contrary.

Many schemes have been devised to seal a rear end cap where it joins its barrel. A tight mechanical seal is usually effective, but sometimes rubber or silicone (high heat) O-rings (or sealants like pipe dope) are used as a backup, in the event that the suppressor loosens as it is being used. For the sake of reliability and cold shot accuracy, it is critical that a suppressor not loosen on its barrel.

If a bullet path is not perfectly straight the holes in suppressor baffles will have to be enlarged to accommodate. Due to angular dispersion, those baffles nearest the muzzle can have holes which are smaller. We live in a real world, not a theoretical one. Most barrels have bent bores. Most bores do not lie in the true center of a barrel. Most suppressors are not perfectly aligned. Threads wear. Welding distorts. That’s why we have tolerances, and sometimes situations require that those tolerances be increased. Tight baffle holes are more important near the rear, where high-pressure gas exists, than they are near the front. Asymmetrical baffles usually work best when they line up parallel to each other. Some manufacturers have a method of holding those baffles in proper alignment. Some just drop them into a tube and hope that they stay aligned.

Front end caps are either welded in place, or screwed in. If the manufacturer wants to be able to get back inside the can at a later date he will use a weak glue or ISPBA (intermediate-strength, proprietary bonding agent – also known as Blue Loctite). If he wants the end caps to stay, he will use a stronger glue, or HSPBA (higher-strength, proprietary bonding agent – IE Red Loctite). Aluminum does not glue well, even with 2-ton psi epoxy. If the can gets hot from rapid use most adhesives will loosen and eventually fail. Even secret, high-strength proprietary bonding agents will eventually give up and work loose at the rear end cap, where most of the heat and shock are concentrated.

Summary

It is difficult to summarize a complex topic in its entirety. Those who use high-powered sniper rifles have every right to expect those rifles to be dependably accurate. A properly suppressed rifle must be constructed with a serious commitment to both suppression and reliable accuracy from the outset. This usually means a steel or stainless steel silencer mounted to a short, heavy barrel with a robust, two-point mount. One can expect both barrel and silencer to exact a combined penalty of at least four or five pounds in weight, and an extra six inches in overall length.

Continued and diligent practice on a regular basis are vital to a mission. Practice should be held at night and during inclement weather, as well as on warm, sunny days. Only a few rounds need be expended, but they should all be accurately and carefully delivered. One should always look through the bore to ensure that it is clear before a callout or deployment. Wasps and other insects have a nasty habit of building mud nests in inconvenient places, and a plug of mud can be disastrous to bullet placement. Always store the weapon muzzle-down. The suppressed rifle must remain dedicated to suppressed fire only. To do otherwise compromises cold shot reliability. The benefits of a suppressed system include a low profile, relative obscurity, increased accuracy, decreased recoil, greater stability, and a lower likelihood of detection in the field.

The Use of Sound Suppressors on High-Powered Rifles: Semester 1

It should be stated at the outset that the phrase high-powered will cover those fairly efficient, non-magnum cartridges bracketed between the .223 and the .308 – the workhorses of the law-enforcement and military community. If one is going to suppress a sniper rifle, that rifle should be totally dedicated to suppressed fire. Using a rifle which is only occasionally silenced is an invitation to either a lawsuit or to poor field shooting, as any rifle will carry a different zero without a suppressor, as opposed to its zero with one.

A suppressed rifle should be stored and carried in its assembled, ready-to-go configuration. Many of us have seen movies in which a fitted case full of components (stock, action, barrel, forearm, scope, mount and silencer) was assembled in the field, and then used to complete an important assassination. Pure Hollywood. No enforcement officer in his right mind would ever assemble a rifle on the spot on a callout at a crime scene and expect the weapon to hold its zero. It might, but such an occurrence would be an abnormality. And what would be the moral and legal consequences of a botched shot in a hostage rescue attempt? By the same token, some suppressors cause shots to stray with various degrees of tightness or looseness on a rifle’s barrel.

The Single-Point Mount

The muzzle and a massive outpouring of high-pressure propellant gas are the last things a bullet feels before it leaves the control of the shooter. The joint between suppressor and barrel should be as rigid as that between barrel and action. Often, the suppressor/barrel interface is conceived as an afterthought. The muzzles of most military barrels are fitted with small, steel flash hiders, weighing but 2 or 3 ounces. Many manufacturers try to use the same kind of short, 1/2 inch diameter, threaded muzzle sections to mount suppressors that might weigh up to 4 pounds. It may be convenient to use flash hider threads, but such a tiny joint is very fragile, and lacks the strength and stability expected of a military or enforcement weapon. A small error in machined accuracy on a single-point mount can result in a disastrous misalignment problem near the muzzle of a suppressor.

A suppressor that is held at the rear by a single collet, or by a single section of threads, is said to be held by a single-point mount. If the threaded section is only 1/2-inch in diameter the strength factor is very low. If a heavy target barrel is used, the threads can be as large as 3/4 or 7/8 inch in diameter. In this case, the strength and stability factor is much improved. Unfortunately, many suppressed rifles with single-point mounts suffer from a wandering zero. There is, however, a better way.

The Two-Point Mount

The two-point mount usually attaches a barrel to its suppressor with threads at the muzzle, and with a collet, O-ring, or conical joint about 8 or 10 inches behind the muzzle. It is a vastly superior way to mount a muzzle can to a rifle barrel. The resulting joint is many times stronger than any single-point mount could ever be. Because of the geometry of a two-point mount, a small error in alignment will not progress into a much larger error at the suppressor’s muzzle.

The common configuration has threads at the barrel’s muzzle, and the step for the rear of the can near the middle of the barrel. Tightening puts the suppressor in compression, and the barrel in tension – which we feel is the most conducive to accuracy. Another configuration has a threaded section in the center of the barrel, while the unthreaded muzzle stubs or jams into a socket in the middle of the suppressor. We feel that this configuration (with the barrel in compression) is not as conducive to accuracy, although it may ease manufacture of the suppressor. However, to our great surprise, we have seen suppressed .308 systems (with compressed barrels) that appeared to be fairly accurate.

Yet another benefit exists with the two-point mount. Space behind the muzzle exists inside the rear chamber of the suppressor. That extra volume can be used for more effective suppression, without adding greatly to the overall length of the weapon in front of the muzzle.

Barrel Torque

Most rifles have barrels that impart a right-hand spin to their projectiles. Since most calibers accelerate their bullets to between 2,500 and 3,400 fps, and since most of this acceleration takes place within the first few inches, there is a sudden and violent twisting of the barrel in an opposite (left-hand) direction. This torque tends to cause a barrel held into its action with RH threads to screw itself ever more tightly into its action with each shot. One can screw a barrel lightly into an action by hand. After several shots are fired the barrel will have driven itself tightly into its action, and it will take quite a bit of force to remove that barrel with a wrench.

That same torque tends to cause a suppressor to loosen if the suppressor is held in place with RH threads, which seem to be the norm. One must be constantly vigilant to make sure that a rifle’s suppressor remains tightly screwed in place. Especially before a critical shot. All Russian and German flash hiders (and some suppressors) are attached with LH threads. Those made in the U.S. are usually held on with RH threads.

Our testing has indicated that a rifle with a suppressor held in place with a properly executed, two-point, conical, tensioned barrel mount will remain in zero. This zero remains even after the suppressor has been removed for cleaning and replaced. As long as the replacement torque is about the same, the zero will be unaffected. We are talking about no discernable, cold shot shift after a day, week or year, at 200 yards.

Suppressor manufacturer Don Wagenknecht, of Grandview, MO (DAW-Phone-816-765-2539) uses a threaded muzzle and an unusual rear collet to hold his high-powered rifle suppressors in place. Don is a skilled and extremely precise machinist. His work is so accurate that he allows a mere .007 (7/1,000ths) of an inch of clearance on each side of his bullets as they pass through a stack of symmetrical baffles. Clearances on baffle stacks of other manufacturers are often significantly greater.

Bullet contact with any one baffle in a suppressor usually results in tumbling, with severe consequences for those baffles that remain downrange of the event. Since the smallest possible passage hole results in the greatest level of suppression, the pressure is on to keep internal baffle clearances to a minimum. More than one suppressor (held with a single-point mount) has been ripped free of its threads, and then violently launched downrange when baffle contact has caused internal bullet tumbling. Damage to the suppressor in such an instance is usually substantial. If this happens in the field the rifle may be undamaged, but it will have to be rezeroed before it can be used effectively.

Moisture Accumulation and Weapon Storage

Water is a major byproduct of gunpowder combustion. A good suppressor will capture and retain a considerable amount of the liquid. Twenty shots from a .308 will cause about a teaspoonful of water to be captured. Whenever possible, the weapon should be carried and stored with the muzzle pointing straight down. The bolt or action should remain open to allow accumulated water to evaporate and vent. If the suppressor is removed as soon as the shooting stops, heat in the suppressor will rapidly dry most of the internal components.

Unfortunately, most rifles are traditionally stored muzzle-up. This causes water and trapped particulates to slowly release, where they will fall and lodge in the chamber area and bolt face. Burned gunpowder is quite dirty, and the inside of a suppressor is usually filthy. Cleaning is best accomplished by flushing the can in solvent, draining, and blowing the unit out with compressed air. One should get in the habit of storing a suppressed rifle by hanging it, muzzle-down. Even stainless steel components will rust if trapped water is not allowed to vent. This may result in a suppressor rusted tightly to its barrel. A bore with rust near its muzzle may lose its accuracy. Corrosion can occur quickly in a warm, moist environment. This is not an aspect to be ignored.

The Blast Baffle and Its Effect on Accuracy

The most critical moment in a bullet’s flight path is just after it exits the barrel, where the highly elastic and more rapidly moving gasses overtake it and press upon its base. The first baffle in a suppressor is called, appropriately, the blast baffle. This is the most critical component in the entire baffle stack. The blast baffle is subject to a great deal of heat, stress and impact. Many baffles have asymmetrical surfaces, and these can bounce the blast of high-pressure gas around in a way that disturbs the stability of an exiting bullet. When we first started experimenting with asymmetrical S, Z and K style baffles this phenomenon became painfully obvious. Keyholing, tumbling and baffle contact were common because the bottle-shaped blast of muzzle gas overtook the exiting bullets, deflected off the asymmetrical surfaces, and then deflected the bullets. Accuracy was not good. Some manufacturers haven’t learned this lesson yet, and their suppressors are plagued with inherent instability and resultant accuracy problems.

The blast baffle must have a perfectly symmetrical, coaxially aligned surface and bore. It must be made of fairly tough steel, stainless steel or inconel. If it is made of a soft material like copper, brass, titanium or aluminum, the high-velocity impact from unburned grains of powder will peen the surfaces – eventually reducing the size of the bore orifice to the point where destabilizing bullet contact results.

A properly designed blast baffle will strip and deflect much of the bottle-shaped blast of high-pressure gas that envelops and pursues the departing bullet. For this reason, one can logically expect an increase in practical accuracy when a properly designed suppressor has been installed. Also, the weight of a heavy steel unit tied to both the center and end of a rifle barrel does beneficial things for harmonic barrel vibration – dampening out much of it. These two factors greatly increase the practical accuracy potential of a suppressed rifle. The properly suppressed rifle becomes very stable and reliable. Larger internal clearances reduce the likelihood of baffle contact in the event that the suppressor or barrel get slightly damaged or bent.

The Supersonic Crack

Any projectile moving through the air at a velocity greater than the speed of sound (1,089 to 1,114 fps in dry, 65 degree F air, depending on who one listens to) will create a supersonic crack. Temperature, humidity and atmospheric pressure variations play a role in raising or lowering the speed of sound by a small percentage. In a firearm which lacks a substantial muzzle report (being fired over an open field) the sound resembles the loud tearing of a bed sheet. Two sounds are actually created, one from the front of the bullet, and one from the rear. Near trees and buildings the sound waves come back as a distinct crack or pop each time the speeding bullet passes some object with a vertical, reflective surface. Once the muzzle report has been diminished the supersonic boom becomes dominant. Curiously, the sound will now appear to come from the target area, rather than the rifleman’s position. Sound moves through our atmosphere at a relatively fixed rate. A sound wave will typically strike one ear a bit before the other. The human brain is capable of detecting the difference in time between sound impacting one ear and then the other — in an increment of as little as one/six-millionth of a second. With time and practice we soon learn to use this ability to pinpoint the source of a sound very accurately. Because a suppressed muzzle report is relatively quiet, the uninitiated will automatically home in on the loudest sound, which in this case is a sonic boom reflecting from the target area. The sound of the bullet’s passage will seem much louder than the muzzle report to someone close to the flight path. Indeed, a rapidly moving .308 bullet will sound louder than a .22 LR pistol, to someone who is positioned a few feet from its flight path.

Smaller diameter bullets make less noise than larger diameter bullets. Supersonic is supersonic. A bullet traveling 1,200 fps will make about the same noise as one traveling 4,000 fps. Projectiles that are .308 inch in diameter will be somewhat louder than .223 bullets. There is no technology which can remove the sound of a supersonic projectile, no matter what claims are made to the contrary.

Sound Level and Recoil

Even though the supersonic crack remains, the overall sound level is greatly diminished. The report sounds like a rapid hiss of compressed air as the slowed gasses issue from the muzzle of the suppressor. The suppressed .223 and .308 rifles become quite comfortable to shoot without hearing protection. Since propellant gas is responsible for about half of a rifle’s recoil, and since that gas is captured and released slowly, the recoil level will be about half that of an unsuppressed rifle. A .308 has a propellant charge weighing about 50 grains. This is of course converted to 50 grains of gas, and this gas only moves forward about 2 feet before the suppressor baffles intercept it. The fact that the gas doesn’t leave the muzzle of the suppressor at high speed is responsible for much of the reduction in recoil. The interception of forward momentum (which results when that gas is captured in the can) is responsible for much of the remainder of the reduction in felt recoil. In addition, the weight of the heavy can on the rifle’s muzzle acts as a pendulum, limiting muzzle rise and swing as the rifle recoils, and then pivots around the shooter’s body mass. We have said all of this about recoil only because many people have a hard time understanding how 50 grains of gas can be responsible for as much felt recoil as 168 grains of rapidly departing bullet. The answer of course is that the bullet, being heavy and inelastic, issues forth at a relatively slow speed when compared to the lighter and (we are told) perfectly elastic gas. Since energy is a product of mass times the square of velocity, it can be seen that the gas doesn’t have to exit many times faster than the bullet to equal its energy. Empirically, we know that recoil from a suppressed rifle carrying a high powder charge is much gentler with a suppressor than without. All theoretical argument stops after that point. If a rifle hurts you to shoot it before suppression, it becomes quite comfortable to shoot after it’s been suppressed.

It should be mentioned that (if a rifle was first sighted in, and then suppressed) the point of impact will be much lower and a bit to the left for a right-handed shooter. We need to say that again. The point of impact will not be the same if the previously zeroed rifle is used with (or without) its suppressor. A rifle simply cannot be zeroed in one mode and then used in the other. This is a serious liability issue for law enforcement snipers. Litigation specialists (lawyers) will hammer this point to exhaustion in a courtroom if a hostage rescue situation ever goes bad as a direct result of a botched shot, or if innocent bystanders are wrongfully injured. The rifle, scope and suppressor must be regarded as a unit, and they must remain as a unit. If a number of suppressed rifles exist in an armory, they must be numbered, and the respective pieces must remain married, so that suppressors stay with their assigned rifles. Identical suppressors on identical rifles may be interchangeable without affecting cold shot zero, but an officer of the law should not take that chance.

The Art of the Rifle, by Jeff Cooper, ISBN 0-87364-931-1, 97 pages, 82 photos, Published by Paladin Press, Box 1307, Boulder, Co 80306, Phone 303-443-7520.

For those who came in late, the venerable Jeff Cooper has been teaching personal self-defense and the arts of rifle, pistol and shotgun shooting for a great many years. He has run thousands of students through his courses at Gunsite Ranch, near Paulden, Arizona.

This philosopher warrior has developed a unique approach in his teaching. In his characteristically Spartan style, Jeff has systematically stripped all of the useless and superfluous away – leaving only the necessary and essential elements. These he lays down in a logical and sequential way. In his personal teaching he is hard, fast, rigorous, regimental and ruthless, but his students achieve very high levels of proficiency in a remarkably short interval of time. Taking a class from Jeff Cooper is very hard work. All who make it through the purgatory, however, are pleased with the level of skill and confidence they’ve achieved. Many of the faithful have been waiting for this book on rifle shooting from Jeff for many years.

If I could only possess one weapon (a distinct possibility, considering the way things are going in this country) that one weapon would be a .308 bolt-action rifle. This book is not about rifles; it is about shooting rifles. It starts by saying that the rifle is the queen of personal weapons. It allows man to be the monarch of all he surveys. In capable hands a good rifle can easily and instantly reach out to defend against a threat out to 300 yards away. In highly skilled hands, that distance may be extended to 600 yards.

In 20 short chapters, The Art of the Rifle logically and sequentially explores and illustrates that which one needs to know in order to shoot a high-powered rifle well. In a nutshell, shooting well means placing first-round hits on appropriate targets rapidly and efficiently. As the veteran hunter or soldier knows, speed is almost as essential as accuracy. To quote Cooper from another source: “The second principal of personal defense is decisiveness. The hunting shot is one seldom fired in a purely defensive mode, but nonetheless it remains difficult for the novice to make the life-and-death decision when necessary. Once you have acquired your target in your sights, do not dally, dither nor delay. Do it right, and do it now. This does not mean that you should rush your shot or mash your trigger, but that once you are on, you go for score. I have seen this practice neglected in the field often enough to feel strongly about it. I do not know exactly how to teach the matter of decisiveness to a student on the range, but the demand remains-If you are going to do it, do it now. Do it right, but do it NOW.”

The Art of the Rifle is now into its second printing after only a couple of months. It is interesting, informative and well written. It is a good read. It’s only 97 pages, but you won’t get through it in 4 hours, and you won’t get it all on the first, second or third reading.