For the past 30-plus years, the name Curtis Higgins and S&H Arms of Oklahoma, Inc., have been at the forefront of quality machine gun conversions of Heckler & Koch (HK) semi-auto rifles and carbines. The business started in 1986 manufacturing thousands of registered HK autosears prior to the May 19, 1986, ban on new machine guns and conversions. Since the 5/19/86 Day of Infamy, Curtis and his company have converted innumerable HK 93, 91 and 94 rifles into fully transferrable select fire versions of the models 33, G3 and MP5 (for more info: curtis@sandharms.com). While several other manufacturers also made the autosears, the S&H conversions were coveted due to the flawless cosmetics and functioning of the weapons. S&H was also known for its autosears for the FNC and, to a lesser extent, autosears for the Ruger 10/22. To this day, S&H is known as the premier gunsmithing facility for HK machine guns.

1986 also was the year S&H entered the suppressor market with MP5 muzzle suppressors, HK MP5SD integral suppressors and a variety of integral rimfire suppressors for Ruger .22LR weapons, the Ruger 77/44 and the Marlin .45 Camp Carbine. Curtis licensed his integral Ruger rimfire designs to John’s Guns.
Small Arms Review recently received S&H’s latest suppressed weapon, an integrally suppressed upper receiver chambered for the popular AAC .300 Blackout cartridge, an improved version of the SSK .300 Whisper originally designed by J.D. Jones.

Designed for a 9-inch barrel, the .300BLK’s popularity has risen dramatically due to the simple conversion of the AR-16/M16 weapons simply by changing the barrel with its associated gas block. Even the M249 belt-fed machine gun is set up for this cartridge. For many purposes, the .300BLK cartridge is ideal: .30 caliber bullet, short barrel, subsonic and supersonic loadings with bullet weights ranging from 110 grains to 220 grains. The loadings using bullets 150 grains or less are supersonic while those with the heavier bullets are generally subsonic.

The S&H Model 30 is a complete assembly consisting of an integrally suppressed upper receiver with an overall length of 28.8 inches and a ported 16-inch, 1:5 barrel. The ports bleed excessive propelling gas into a sealed chamber in the rear of the suppressor.  It weighs 89.7 ounces (5.6 pounds). It utilizes the bolt, charging handle and lower receiver of the user’s AR-15 or M16. For our evaluation, we used a Bushmaster select fire AR-15 lower receiver with a standard buffer intended for 5.56 weapons.

The unit is a conventional direct impingement gas system which mounts easily on an AR-15 or M16 lower receiver using the bolt assembly and charging handle from the host weapon. The handguard has a full-length Picatinny rail and has as standard equipment easy-to-use, flip-up sights. The 1.5-inch-diameter suppressor outer tube extends rearward over the barrel over 15 inches back to the gas block and approximately 5.5 inches forward of the muzzle. The baffle stack in this forward section contains five conventional baffles. The exit hole in the front end cap is configured to use a standard 3/8-inch hex wrench for disassembly. The large chamber surrounding the barrel is fed by four ports in the barrel several inches forward of the gas port. This permits proper usage of this chamber rather than relying on reverse gas flow at the muzzle.

The entire suppressor can be disassembled by the user for cleaning and maintenance. The only tools needed are a 5/32-inch hex wrench for the handguard and a 3/8-inch hex wrench for the front end cap. For total disassembly, a special spanner wrench from S&H is needed to loosen the retaining nut that tightens the suppressor outer tube onto the threaded barrel end. Removal of the baffles and spacers from the front section is somewhat tedious. Unlike firearms with moving parts, suppressors generally perform better if they are not cleaned (with the exception of rimfire suppressors). From the writer’s experience examining suppressor designs, it is estimated that performance degradation will not become apparent for many tens of thousands of rounds, and cleaning is not recommended.

Of major interest to users is the sound performance of the system. Sound measurements were made in compliance with MIL-STD-1474D (Section 5). Two Larson-Davis model 800B sound level meters were used, each with its Larson-Davis model 2530 random incidence ¼-inch instrumentation microphones. These are compliant with rise/response times less than 20 microseconds. Measurements were made at the reference location (one meter left of the muzzle 90º to bore axis, 1.6 meters above grass) and at the simulation of the shooter’s left ear (SLE, 8cm rearward of the receiver, 18cm left of bore axis). By using two sound meters, it is possible to obtain both location readings for each shot. Because MIL-STD permits the use of weighting and because weighting is the industry standard, measurements were made utilizing C-weighting.

Five rounds of 125-grain Black Hills supersonic, five rounds of Gemtech 187-grain subsonic, five rounds of TNQ 220-grain subsonic and five rounds of Remington 220-grain subsonic ammunition were used, and the results averaged. In addition, velocity was measured both at the muzzle and at 25 yards using a Labradar radar chronograph. Velocity at greater range was not possible due to constraints of the range used. Sound levels and velocities are shown in Table 1.

While performing sound testing, several malfunctions were noted with the Gemtech 187gr, the TNQ 220gr and the Remington 220gr subsonic ammunition. The 125gr Black Hills supersonic functioned flawlessly.  Because of malfunctions with the subsonic ammunition, high-speed video was taken, concentrating on the ejection port to document actual bolt travel and rearward bolt velocity. Video tests were performed on a 3-shot burst with the camera operating at 10,000 frames/second. The TNQ 220-grain subsonic was not photographed due to having only enough ammunition to perform sound and velocity measurements. The high-speed video of the bolt opening showed normal rearward travel with the supersonic ammunition but only approximately 66%–75% rearward travel with the subsonic ammunition.  Opening bolt velocity was 3750mm/second with supersonic ammunition and less than 2,000mm/second with subsonic. The subsonic bolt travel was enough to permit case ejection at the 4 o’clock position but not enough to feed the next round from the magazine.

Sound levels with all varieties of ammunition tested were below 140dB at the reference location with the subsonic ammunition showing averages around 130dB. Readings at the shooter’s left ear location were in the upper 140dB region, probably due to some ejection port noise and gas leakage in the region of the gas block. Supersonic readings were somewhat higher than subsonic. The reference location is a good indicator of perception by the target in the far field.

Velocity readings were as anticipated for the ammunition used. All subsonic ammunition had a muzzle velocity just under 1,000 feet/second, and all exhibited a drop of approximately 50 feet/second at 50 yards. The Remington 220gr subsonic exhibited the greatest round-to-round variation in velocity with a standard deviation of around 30. The TNQ 220-grain subsonic showed the least variation.

Quantifying flash requires a light meter capable of holding the intensity of the single brightest light peak. Lacking access to such a meter, there are two methods of evaluating flash: long camera exposure (about 1 second) on a dark night or high-speed video. High-speed video offers the option of performing filming in daylight with a black background for contrast. It also offers the option of looking at bullet stability. With a ruler in the field of view, a reasonable estimation of the intensity can be made. Figure 5 is the single frame showing the greatest amount of flash.

Firearms have little value if they are not accurate. A lead-sled was used as a bench rest, and a target was shot at 50 yards. It was decided to utilize the Black Hills 125gr supersonic ammunition because its greater kinetic energy is most likely to be used for neutralizing targets. The supply of this load was limited without enough to zero accessory optical sights. As a result, the flip-up iron sights on the weapon were used. The front post (.058 inch) is approximately 6MOA wide. The group size is under 3MOA (target grid is one inch).

In all, SAR’s testing of the S&H M30 integrally suppressed upper receiver was very positive. While it is a larger suppressor, it is also very successful for 300BLK suppression and accuracy. Curtis should be proud of his continued success in providing a good product for the end users.

This article first appeared in Small Arms Review V22N9 (November 2018)

Ruger Silent-SR Series Suppressors

Sturm, Ruger & Co., Inc. is the quintessential example of American capitalism at its best. The company was founded with a meager $50,000 investment by William B. Ruger and Alexander M. Sturm in a small, rented machine shop in Southport, Connecticut in 1949 for the purpose of manufacturing firearms. At that time, there were serious doubts within the industry with insider experts saying that “it can’t be done,” and that the entire industry was in decline. It was assumed that the large established name gun makers would continue to dominate the market.

What the industry didn’t count on was that this new company was guided by a number of innovative concepts, not the least of which was William B. Ruger’s desire to build each product “to a standard so that I would want one even if it was made by our competitors.” These basic principles of innovation, quality and value have earned the company the position of pre-eminence in the firearms industry over the past 68 years. Ruger, which is one of only two firearms manufacturers traded on the New York Stock Exchange, produces millions of firearms each year for hunting, target shooting, collecting, self-defense, law enforcement and government agencies.

Ruger’s first product was the Ruger Standard pistol in .22LR. With some design innovations inspired by the Japanese Nambu and cosmetics/ergonomics of the German Luger, it became wildly popular—it was comfortable to hold and shoot. A retail price in the 1950s of $37.50 (representing fewer than 40 hours minimum wage effort), decent accuracy and good reliability were winning factors. Designed with manufacturing economy in the forefront, it had a 4.75-inch barrel and fixed sights. Many a bullseye match shooter had one in the bottom of his bag to permit finishing a match when his finely tuned target gun malfunctioned. It was also found tossed in the bottom of fishermen’s tackle boxes. Its popularity (and that of the 10 /22 rifle) started an ever growing industry of accessory makers.

Ruger is no stranger to the National Firearms Act weapons, having developed and built several machine guns. In the late 1980s Ruger purchased the rights to the UZI and what became the MP9 from Uziel Gal, its designer. In 1995, Ruger introduced its MP9 9mm submachine gun. Although recognized as an improved UZI, the weapon never became popular or even well known. Bill Ruger held the belief that civilians should not have access to machine guns and established the company policy that no Ruger machine guns would ever be sold to civilians, including Class 3 firearms dealers. The market was to be domestic law enforcement and international military. However, noted in the company’s law enforcement catalog, marketing to law enforcement requires personal demonstrations by local Class 3 firearm dealers. The MP9 was discontinued in 1996. Ruger’s other venture into the machine gun market was a variant of their 1973 Mini-14, the AC-556, which looked exactly like the Mini-14 but had a selector switch (semi, burst, full-auto) at the receiver right rear. The standard AC-556 was offered in both blued and stainless versions as well as a shorter weapon with a folding stock and 13-inch barrel (AC-556K or AC-556F) in blue or stainless. With marginal sales (although far better than the MP9), production was discontinued in 1999 and support terminated 10 years later. Until William B. Ruger’s death in 2002, no Ruger machine guns were sold to civilians. The civilian marketplace was through sale of police trade-ins.

Part of Ruger’s success has been through good market research, outstanding engineering and production of innovative products without significant bureaucratic impediments to slow down development. Part has been financing through reinvestment of profits rather than using traditional debt structure. And part has been by doing manufacturing in-house. Ruger’s Pinetree Casting (Nashua, NH) is one of the foremost investment casting facilities, and in addition to many Ruger weapon receivers, does casting for golf clubs. In 2014, the company purchased Megamet Solid Metals Inc., based in St. Louis, Missouri, to add metal injection molding (MIM) casting capability not only for increased production capacity, but to markedly reduce development time for new products. Unlike many of its competitors, Ruger has not acquired related companies, either competitors or accessory makers.

The use of silencers has become mainstream over the past 4 to 5 years, a fact not overlooked by Ruger. Although their 10 /22 rifles sold in the international market were routinely threaded 1 / 2-20 for European rimfire silencers, it wasn’t until several years ago that domestic Ruger .22 rifles and pistols came threaded 1 /2-28 for the US market. Ruger looked at possible acquisition of a silencer company but after due diligence decided to start building suppressors in-house at their New Hampshire facility.

Approximately a year ago, Ruger introduced two sound suppressors designed for rimfire cartridges: the “Silent-SR” thread mounting muzzle suppressor and the “Silent-SR ISB” integrally suppressed barrel for their take-down 10 /22 rifle.

Both suppressors are attractively packaged in boxes with a fitted foam insert. Any necessary tools are included: a cast composite spanner wrench for removing the endcaps of the Silent-SR and a hex wrench for disassembling the integral Silent-SR ISB. All suppressors are supplied with a 12-page, well written and profusely illustrated manual that covers legal and safety aspects, specifications, attachment to the host weapon, use, disassembly and cleaning instructions. Disassembly for cleaning is simple, and it is virtually impossible to reassemble incorrectly. Both are finished in black Cerakote.

Testing Protocols

The first question posed by most users relates to sound performance since that is the stated goal of a sound suppressor. There are a number of ways to evaluate sound levels, starting perhaps with Mitch WerBell of Sionics fame in the 1970s where he lined up the office staff and shot two different suppressors behind their backs asking which was quieter. While this has merit in distinguishing suppressed from non-suppressed weapons, subtle differences are distorted by the individual hearing damage of different observers.

A more objective method is to use sound measuring equipment that meets the requirements of MIL-STD-1474D. Not all sound meters are capable of accurately measuring the short peaks of firearm sounds, and even some industrial precision meters do not have the necessary peak detector. There are two classic field portable sound meters that meet all the requirements of MIL-STD-1474D: the B&K 2209 and the Larson-Davis 800B with their appropriate ¼-inch pressure microphones. Originally costing in the $5,000 range, both are currently out of production but are frequently available at reasonable cost. Factory service and recertification services are still available. For testing both Ruger suppressors, two of the L-D 800B meters were used, both of which were recertified by Larson-Davis 4 months prior to this test.

MIL-STD calls for a number of measurement locations. For the purposes of the most meaningful and familiar results, sound levels were measured simultaneously at the standard Reference Location (1.6 meters above grass, 1 meter left of the muzzle 90O to bore axis) and at a simulation of the shooter’s left ear (SLE). The Reference Location gives an indication of how the target or down range observer will perceive the gunshot, and the SLE will give one of the better indications as to potential hearing damage. While some advocate using the shooter’s right ear, close contact with a rifle stock confuses weapon action noise with muzzle blast reduction. The simulated SLE positioning of the microphone is 8 centimeters rearward of the back of the receiver (70 centimeters in the case of a handgun) and 18 centimeters left of the bore axis. By measuring both locations simultaneously for each shot, variations in individual rounds are minimized.

For each weapon-suppressor combination, three rounds were fired non-suppressed, and the results averaged. This was followed by a five-round string with the results averaged. It has been found that this number of rounds is statistically significant. For each location, the averages and reduction are noted. In addition, first round pop is calculated by subtracting the average of the last four rounds from the first round. First round pop is caused by a secondary detonation of partially burned powder particles encountering oxygen in the suppressor. MIL-STD permits the use of weighting scales. For a number of years dating back into the 1970s, A-weighting was used. In recent years, a number of manufacturers have changed to C-weighting, which is more accurate for the sound levels encountered with firearms.

Both OSHA and MIL-STD-1474D state that hearing protection is required for short duration peak sound levels greater than 140 dB at the shooter’s ear.

A second item of concern in evaluating a suppressor is whether there is any degradation in accuracy (group size) when the suppressor is mounted. There is often a shift in point of impact which can be corrected by sight adjustment. Rifles were used in a solid rest (Lead Sled) for group size measurements both with and without the suppressor at a range of 40 yards.

For handguns, high speed video was performed looking for excessive yaw or tumbling with the suppressor in place. Frame rate was 5,000 frames/second with a shutter speed of 30 microseconds to provide stop action of the bullet in flight during the first 2 feet of travel. The high-speed camera used was a monochrome Olympus iSpeed FS.

A third concern primarily of military importance is night-time recognition of the shooter’s location from flash or heat signature visualization. Because these suppressors are designed only for rimfire, flash signature was evaluated using high-speed video and only when mounted on the MK-II pistol (generally the worst case scenario).

With either suppressor, it is necessary to utilize standard velocity or subsonic .22LR ammunition to avoid the ballistic crack found with high-velocity ammunition. This crack has been measured with CCI Mini-Mag ammunition at 142 dB 1 meter to the side of the bullet flight path. In the case of .17HMR or .22 Magnum ammunition, the ballistic crack of the supersonic projectile is acceptable, and live targets are confused because the suppressor masks the origin of the shot.

Test Conditions

November 4, 2017, was a bright, sunny fall day in Boise, Idaho. The temperature was a chilly 50F with a relative humidity of 37% and a station pressure of 686 mmHg. Wind gusts were less than 3 miles per hour. The speed of sound calculated to 1,107 feet/second.

The ammunition chosen for testing was CCI Standard Velocity .22LR with the 40 grain bullet. This was chosen because it is commonly available, accurate and remains subsonic in almost any barrel length chambered for .22LR.

The Silent-SR thread-mounting suppressor was tested on two weapons. One was a Ruger MK-2 pistol with a bull barrel shortened to 4.5 inches and mounted in a Ransom Rest. The other was a Ruger 77 /22 with the barrel shortened to 16 inches. The Silent-SR ISB was tested on a Ruger 10 / 22-TD, its normal host weapon.

Silent-SR Thread-Mount Suppressor

The Silent-SR is packaged inside a black ballistic nylon pouch with a convenient belt loop. The suppressor length is 5.4 inches, outside diameter is 1.05 inches, and the weight is 6.4 ounces. It is rated for .22 Magnum and .17HMR in addition to fully automatic .22LR. The length of the threads in the mount is .43 inches, standard for the industry, with a .12-inch thread relief in the mount for safe use with barrels not having a thread relief. The threaded mount is a part of the entrance chamber. There are a total of six baffles (type 17-4 stainless steel), all having a bore aperture of .25 inch. The front end cap functions as a seventh baffle. The rear (blast) baffle is symmetric, and the remaining baffles have significant asymmetry. All baffles have a general conical shape with integral spaces. The tight bore aperture requires barrel threads with a true 90O shoulder for alignment.

Sound measurement levels were obtained on both a Ruger MK-II pistol (4.5-inch barrel) and a Ruger 77 /22?bolt action rifle (16-inch barrel). Both of these weapons are used routinely by the author for rimfire sound measurements. Sound performance was excellent as shown in Table 1 with the absolute sound level at the reference location of 120 dB on the MK-II and 116.7 dB on the 77 /22 rifle.

It is important to remember that there will be day-to-day variations in the sound levels that appear to vary with location, humidity and ambient air temperature. Measurements made in a coastal location do not always correlate with those made in a high desert location such as Boise, Idaho. As a rule, five-round strings are statistically valid (standard deviation <1.5), which is why the tables include the standard deviation for the five suppressed measurements. The one exception was measurement at the reference location where the 8 dB first round pop increased the standard deviation. However, calculating excluding the first round resulted in an average of 118.4 dB and a standard deviation of 1.1, which is in line with all other measurements.

Although what is normally asked is the reduction, the more important measurement is the absolute sound level, both for far field and for hearing risk evaluation. First round pop can be eliminated with either an inert atmosphere (nitrogen, carbon dioxide, etc.) or a tiny amount of oil or grease in the entrance chamber. Absolute sound levels for the rifle are considerably lower than for the pistol, but the degree of reduction is significantly less. This is simply because the non-suppressed level on the rifle is significantly lower than on the pistol.

Accuracy and bullet stability were checked differently on the two weapons. With the Silent-SR mounted on the 77 / 22 bolt action rifle, a target was shot with and without the suppressor at a range of 40 yards. Adding the suppressor moved the point of impact down .176 inches (.421 MOA) but tightened the group from .795 inches (1.9 MOA) to .688 inches (1.64 MOA) with three shots touching. See Target 1.

A check of bullet stability on the MK-II pistol was considered difficult lacking optical sights. Instead, a high-speed video (5,000 frames/second) was performed. Lighting was difficult lacking bright sunlight, so two compromises were accepted: 1) a shutter speed of 30 microseconds (instead of the preferable 2 microseconds and 2) image enhancement (which decreased resolution). Eleven consecutive frames showed the bullet in the first 24 inches forward from the end of the suppressor. These 11 photos were superimposed to show the progress of the bullet traversing this distance as shown in the photo. Starting at the 20-inch region, there is slight yaw, which is normal as the bullet transitions from rotating about its physical center to rotating about its center of gravity. There was no visible flash detected.

The manufacturer’s suggested list price for the Ruger Silent-SR thread mounting suppressor (model 19000) is $449.

Silent-SR ISB for the Takedown 10/ 22-TD

The Silent-SR ISB is a complete replacement barrel with integral suppressor assembly for the Ruger 10 / 22-TD rifle. Unlike similar offerings, the Ruger suppressor includes all hardware and the forend composite handguard. The suppressed barrel is 16.12 inches long, making it .5 inch shorter than the standard barrel, and weighs 41.9 ounces as contrasted to the 30.7 ounces of the standard barrel. The suppressed barrel bears a resemblance to the over/under double-barreled shotgun with a width of .925 inches and height of 1.52 inches. The bore aperture throughout the baffle stack is .280 inch.

The suppressed barrel is alloy steel and 10.62 inches long. The aluminum suppressor outer housing has been permanently attached to this barrel to make the overall length in compliance with BATF regulations. The front end cap and baffle stack are easily removed by loosening the assembly bolt, a process well described in the manual. The blast baffle is symmetric, and the remaining six are significantly asymmetrical. All are type 17-4 stainless steel.

Sound measurements were made using the same host 10 / 22-TD receiver and comparing the original non-suppressed barrel with the Silent-SR ICP integrally suppressed barrel. The results are shown in Table 2. The suppressed barrel measured an impressive 114.7 dB at the reference location, which is only approximately 4 dB louder than the hammer falling on a spent cartridge case.

Accuracy testing was performed in the same manner as for the thread mounting suppressor on the rifle. The range was 40 yards, and the weapon was shot using the Lead Sled rest. A fixed 10x scope was attached to the Weaver base supplied with the rifle. Five shot groups were fired with both the standard and suppressed barrels. The target is shown in Target 2. The suppressed barrel tightened the group from 2.9 inches (6.92 MOA) to 2.05 inches (4.9 MOA) and dropped the group center by .77 inches (1.84 MOA).

The group sizes, both suppressed and non-suppressed, were considerably larger than with the thread-mounted suppressor on the 77 /22. There are several reasons for this, not the least of which is a re-worked 2.5-pound honed trigger on the 77 /22 with no over-travel as compared to a rough 6-pound trigger on the 10 /22-TD with significant over-travel.

The second issue is with barrel lockup on take-down weapons. The 10 / 22-TD tensioning ring has to be adjusted when one barrel is replaced with another. The tension at lockup is not totally consistent, and there is the potential for almost imperceptible flex at the barrel/receiver joint. Even simple removal and replacement of the same barrel can cause a minor point of impact shift. The most accurate way to mount an optic on a take-down rifle is to mount it on the barrel rather than the receiver. In contrast, the 77 /22 barrel is mounted in a far more rigid manner using a V-block and torqued mounting screws.

The manufacturer’s suggested list price for the Ruger 10 /22-TD Silent-SR integral suppressed barrel (model 19001) is $629.

Comments

Both suppressors have their strong points, including excellent sound performance, tightening of the shot groups and obvious quality. The Silent-SR ISB for the 10 /22 Takedown is definitely the more compact weapon due to the requirement for a 16-inch minimum barrel length. What would be a worthwhile improvement to the integral Silent-SR ISB would be to supply a rail contoured to the .920 diameter of the steel portion of the barrel for barrel mounting of an optical sight. The thread mounting Silent-SR has the advantage of a wide variety of weapon platforms and the strength to hold up to multiple rimfire cartridges. While both are outstanding, the author has a bias for thread mounting suppressors because of their versatility.

SureFire LLC
RYDER 9-MP5

The stainless-steel-constructed RYDER 9-MP5 is a duty-use suppressor for the H&K MP5 sub-machine gun. The suppressor attaches to a standard three lug barrel via our patented Fast-Attach mechanism, similar to the way our best-in-class SOCOM Series suppressors attach. The suppressor is easily disassembled for cleaning, and the baffles are indexed and numbered for ease of reassembly. Designed for duty use, the RYDER 9-MP5 does not affect bullet performance or increase point of impact/point of aim as is the case with other sub-machine gun suppressors. When it comes to durability, performance, and ease of maintenance, the RYDER 9-MP5 is the clear choice for suppressing the MP5. www.surefire.com

SF RYDER 9-MP5
Caliber: 9mm
Length: 8in (20.3cm)
Weight: 15.6 oz (442g)
Diameter: 1.30in (3.3cm)
Material: Stainless steel
Finish: Cerakote
MSRP: $849

SRT Arms
SRT Integral M-16 / 9MM Uppers

Integrally suppressed 9MM AR15/M16. Integral suppressed upper, 9MM or .45 ACP., 1.5” OD tube. Pinned and welded 16” bolt face to end of tube, or removable for registered MG or SBR lowers. Ported barrel for additional sound reduction.Porting available to make 115 gr subsonic, or max velocity for use with 147gr subsonic. www.srtarms.com

Weight: Adds 1 lb to upper weight.
4130 tube, 7075 AL baffles and end caps.
Finish: Black Cerakote finish.
Absolute db at muzzle is 116-119 db depending on bullet weight.
MSRP: $780 using customer supplied barrel, handguard and upper receiver.

B&T AG
M.A.R.S. QD

Based on combat experience in Iraq, Afghanistan, B&T has analyzed evolving needs of operators and has evolved its products to perfectly serve the new needs. The new M.A.R.S. QD (Miniature Assault Rifle Suppressor–Quick Detachable) offers greater flash reduction, lighter weight and smaller size. For those who prefer the option to be able to mount/dismount the suppressor even during an operation, the M.A.R.S. QD is the perfect choice. It is the lightest quickest detachable mounting system on the market today. www.bt-ag.ch

Caliber: 5.56mm (.223) or 7.62mm (.308)
Length: 161mm (5.56mm) / 192mm (7.62mm)
Diameter: 39mm
Weight: 415 g (5.56) / 480 g (7.62)
Factory-Tested Sound Reduction: 26 dB (5.56)
Materials Inconel/Thermax Finish: sandblasted/grey
MSRP (USD): tba

B&T AG
M.A.R.S. DM

The M.A.R.S. DM (directly mounted) is the lightest and shortest assault rifle suppressor B&T produces. It´s screwed directly on the muzzle. This lack of any mounting system allows it to be almost 300 grams lighter and 50mm shorter than other suppressors with a mounting system. Therefore the impact on the balance of the weapon and the extension of the gun is negligible and not perceptible in combat. Despite its small size the M.A.R.S. is a full gown up suppressors when it comes to muzzle flash and sound reduction. www.bt-ag.ch

Caliber: 5.56mm (.223) or 7.62mm (.308)
Length: 126mm (5.56mm) / 142mm (7.62mm)
Diameter: 39mm
Weight: 380 g (5.56) / 450 g (7.62)
Factory-Tested Sound Reduction: 20 dB (5.56)
Materials: Inconel/Thermax
Finish: sandblasted/grey
MSRP (USD): tba

SRT ARMS
Integrally Suppressed 9mm AR-15/M16

Integrally suppressed upper, 9mm or .45 ACP, 1.5-inch OD tube. Pinned and welded 16-inch bolt face to end of tube or removable for registered MG or SBR lowers. Ported barrel for additional sound reduction. Porting available to make 115gr subsonic or max velocity for use with 147gr subsonic. www.srtarms.com

Caliber: 9mm
Weight: Adds 1lb to upper weight
Diameter: 1.5in
Material: 4130 tube, 7075 AL baffles and end caps
Finish: Black Cerakote
Factory-Tested Sound Reduction: 116-119 dB depending on bullet weight
MSRP: $780 using customer supplied barrel, handguard and upper receiver

ELITE IRON
DELTA MOD2

The Elite Iron DELTA MOD2 is a shorter version of the popular DELTA and is designed for .223 /5.56 rifles only. The compact design and lighter weight makes it a great choice for hunting and tactical applications. Baffle core design minimizes the POI shift. Thread pitch ½ -28. Full-auto rated. www.EliteIron.com

Caliber: .223 /5.56 only
Overall Length: 6.375in
Exterior Diameter: 1.5in
Weight: 17.9oz
Sound Pressure Level Reduction: 35 dB
Materials: Tube is made from 316 SS. Internals are machined from 17-4 H900 SS
Finish: Black Cerakote
MSRP (USD): $720

ELITE IRON
ECHO LITE 5”

The all titanium ECHO LITE 5-inch suppressor is primarily designed for use on handguns and can be used on rifles as well. It delivers solid performance in a lighter suppressor. The ECHO LITE 5-inch can be disassembled for cleaning. Includes takedown tool. Thread pitch 1/2-28 x .400. www.EliteIron.com

ECHO LITE 5”
Caliber: .22 LR only
Length: 5in
Weight: 4.7oz
Diameter: 1in
Material: Titanium
Finish: Black Cerakote
Sound Pressure Level Reduction: 31 dB High Velocity, 35 dB Subsonic
MSRP: $455

LIBERTY SUPPRESSORS
The Sovereign

The Sovereign rifle silencer is perfect for the law enforcement officer, hunter as well as the long-range shooter. It combines lightweight with numerous mounting solutions to create the most versatile and lightweight silencer to date. Titanium construction provides superior strength as well as low muzzle weight for less fatigue in the field. Combined with our LS1 muzzle brake mount, this is the ultimate package. www.libertycans.net

Caliber: 7.62mm
Overall Length: 7in
Exterior Diameter: 1.625in
Weight: 12.5oz
Sound Pressure Level Reduction: 33+ dB
Materials: Titanium/Stainless Steel
Finish: Black Cerakote Type C
MSRP (USD): $1,050

DAKOTA SILENCER
Varminter 4.0

Varminter 4.0 will be available early 2018. The Varminter is a 100% titanium hybrid that’s modular from 9 inches to 7 inches. It’s a hybrid because the 2-inch extension is a uniquely designed monocore baffle system while the 7 inch is all stacked baffles. The Varminter is completely serviceable and comes all the way apart for easy cleaning. Only the Varminter 4.0 .30 calibur will be modular, but Dakota Silencer will also be releasing the Varminter 4.0 in a .223. This will be the quietest Varminter the company has made to date. www.dakotasilencer.com

VARMINTER 4.0
Caliber: .30 and .223
Length: 7in; 9in with extension
Weight: N/A
Diameter: N/A
Material: Titanium
Finish: N/A
Sound Pressure Level Reduction: N/A
MSRP: N/A

THOMPSON MACHINE
The Poseidon 9mm

In production since 2009, the Poseidon 9mm is the smallest, lightest, hearing-safe 9mm suppressor on the market. Its excellent performance on .22LR hosts, .32acp hosts, and .380acp hosts gives it the versatility to match. The Poseidon is in use with military and law enforcement. www.thompsonmachine.net

POSEIDON 9MM
Caliber: 9mm
Length: 4.125in
Weight: 4oz
Diameter: 1.25in
Material: Hard anodized 6061 and 316 Stainless
Design: Monocore, Take-Apart Design
Suppression: Up to 25dB when wet and wiped
MSRP: N/A

About the Author

Dr. Philip Dater has been involved in the sound suppressor industry for over 40 years as Automatic Weapons Company (New Mexico) and Antares Technologies, Inc. His interest has been in the field of design, testing and manufacturing. He founded Gemtech in 1993 and retired in the summer of 2017 at the age of 80. He continues to consult and perform testing on a part-time basis, and several times each year teaches his signature course “Silencer History, Technology & Testing” at Phoenix Defence in Henderson, NV. www.phoenixdefence.com

Little is known in the Western world of the Soviet silent pistols utilizing special silent ammunition. The package consists of the model PSS (Pistolet Sptsialnyj Samozaryadnyj) silent pistol and the special SP-4 captive piston ammunition. The testing performed consisted of evaluation of the basic handgun, the special ammunition, sound pressure measurements, muzzle velocity, and terminal performance.

In this report, a mixture of English and metric parameters are used. All linear and circular dimensions are metric (millimeters). All weights are grains simply because the convention we use are to weigh bullets and powder in grains. Velocities are English and in feet/second because those are the units of our chronograph. Sound levels are decibels (reference zero dB as 20 micropascals). Temperatures are dual units (F/C) and barometric pressure is in millimeters of mercury.

PSS Pistol

This finely crafted semiautomatic handgun is a magazine-fed weapon utilizing a single stack magazine that holds 6 rounds and a last-round slide hold-open device. The pistol is well finished, and all parts carry the pistol’s serial number. With the finish and serialization of all parts, it appears that during factory assembly on all examples seen by this author, all parts were hand fitted. It is issued with a brief instruction manual (in Russian) and a somewhat flimsy tan leather shoulder holster.

The PSS and its specialty SP-4 ammunition were specifically designed for elimination of live targets without risking discovery of the operator. Unlike predecessor captive piston handguns, the PSS is capable of semiautomatic fire. Although there is a definite advantage to rapid follow-up shots, the disadvantage for the covert operator is that it ejects (and leaves) spent cases at the scene. These spent cases are exceptionally distinctive, and almost anyone with an even passing familiarity with this weapon will be able to identify its use from the spent cases.

It is not obvious where either the PSS pistol or its SP-4 ammunition is manufactured, but other clandestine special purpose weapons have been built at Tula Arsenal, and it is suspected that Tula may well be the origin of the PSS. The weapon carries absolutely no markings other than a low four digit serial number. The PSS was developed for special personnel of the Soviet KGB and for elite elements of the Spetsnaz of the Soviet Army and was introduced around 1983. It is currently used by many elite Russian anti-terrorist teams. It is far more compact and has a quieter action than the more common Soviet PB (silenced Makarov) and Chinese Type 67 silenced pistols.

While the PSS resembles a somewhat large conventional blowback pistol, it is definitely unique. It will accept no ammunition other than the SP-4 silent cartridge. Other than the ammunition used, the most obvious is it has a two-part barrel. The separate distal rifled part is fixed to the frame. The breech portion (consisting of the chamber) is allowed to recoil inside the frame for a short length against its own return spring. This increases the mass of the moving parts at the initial stages of recoil, and also slows the slide on its final stages of movement, resulting in dampening the sound of the slide hitting the stop on the end of the recoil cycle. The slide return main spring is housed in the slide, above the barrel, and the spring guide rod is part of the slide retaining assembly. The PSS firing mechanism is single/double action with open hammer and slide-mounted safety/decocker of conventional Makarov design. Sights are fixed.

We were granted the opportunity to extensively examine (including total disassembly), photograph, and fire the PSS at a discrete Southwest Asian military arsenal. To the best of our knowledge, there are no examples of this weapon in the United States at the time of writing. There are known to be several examples in the United Kingdom. Distribution through the former Soviet satellite countries is unknown but presumed to have been issued to clandestine units in these countries. Total production is unknown.

Because all products of combustion are contained within the spent cartridge, there is no powder fouling or possibility of corrosion from powder residues. Interestingly, this also means that the operator’s hands will not be contaminated with powder residues, which may be of interest in the forensic community. Maintenance consists simply of light oiling of the weapon and wiping the external surfaces with an oily rag.

We do not have available to us at this time a factory breakdown of parts. Because of this, the names we use are based on apparent function and similarity to parts in more conventional pistols. Field stripping for basic cleaning and lubrication can be accomplished with no tools other than a section of cleaning rod. Before starting, the magazine must be removed and the hammer cocked. Although not photo detailed, the accompanying pictures show a slot cut in the front assembly locking piece, which also appears to function as the slide stop. This engages a cut in the front of the recoil spring, limiting rearward motion of the slide. To field strip, a section of cleaning rod is inserted into the recess in the top rear portion of the slide, and the recoil spring guide rod is pushed forward until the locking piece/slide stop clears the front end of the barrel. At this point, the locking piece can be slid upward to disengage from the front of the recoil spring guide rod. The slide then removes to the rear, but the forward end of the slide must be disengaged upward from the rear of the floating chamber, before it can be fully removed. Re-assembly is the reverse.

While we completely disassembled the PSS, we can most definitely recommend that the user never do more than simply field-strip the weapon for maintenance. Total disassembly is quite difficult and is by no means intuitive. It is also totally unnecessary. Re-assembly is even more difficult. We speak from experience.

SP-4 Ammunition

Captive piston ammunition is a unique, special-purpose cartridge that is designed to be intrinsically quiet as compared to conventional ammunition. Essentially, the SP-4 silent cartridge consists of a reinforced steel cartridge case containing a small powder charge enclosed in a cup-like piston in the rear of the case. This piston rests against the base of the projectile; a cylindrical bullet made of mild steel and fitted with a brass driving band at the front. The SP-4 cartridge was adopted by the Soviet KGB and Spetsnaz units in 1983 along with the PSS host pistol.

The ammunition is issued in plain white boxes of twelve cartridges each. The only markings on the box are what appear to be a lot number. This is enough to charge both magazines. There are 20 boxes in a hermetically sealed SPAM tin and two tins in a wooden crate. The tins are marked with the cartridge designation, lot number (that correlates with the number on the boxes), and some other markings of unknown meaning.

Many prior designs, such as the SP-3 and PZAM silent cartridges, utilized 2-part (or 2-stage) piston that extended beyond the end of the cartridge case. While this permitted greater acceleration of the projectile, it also was incompatible with cycling in a semiautomatic host weapon. These older silent cartridges from the late 1970s and early 1980s utilized the standard 7.62mm M43 projectile loaded in the AK 7.62×39 rifle cartridge.

When fired, the primer ignites the powder charge, and the rapidly expanding gases drive the piston forward at a high acceleration. The piston, in return, drives the projectile. When the driving piston reaches a shoulder at the end of the case, the piston is somewhat violently stopped by a shoulder on the front of the cartridge case. Having been accelerated, the projectile engages rifling in the short barrel and exits the weapon toward its target. The high pressure propelling gases are contained (and trapped) in the spent cartridge and gradually leak out over a period of several weeks. Because the propelling gases are not released into the atmosphere, there is very little sound generated.

What this means is that although the pistol is highly specialized to fire this specific round, it is the ammunition itself that is “silent.” In the United States, each individual round is considered to be a silencer subject to the registration/transfer requirements of the National Firearms Act in its various incarnations.

In addition to shooting, we had the opportunity to disassemble a loaded cartridge to examine, photograph, and measure the parts. An inertial hammer-type bullet puller easily dislodged the projectile itself. The piston has a conical projection on its front, which inserts into a hole in the base of the bullet. The purpose is to keep the projectile centered as it is being accelerated during firing.

We decided to fire the case after pulling the bullet in an attempt to drive the piston out intact. The necked-down portion of the case was quite successful in keeping the majority of the piston captured. However, the forward portion of the piston separated and was recovered from the backstop used. We estimate that the dimensions of the piston are in the vicinity of 8.91mm diameter and possibly 5-8mm length. Once some of our fired cases bleed off pressure, we will section one and get better piston length.

The rimless SP-4 case measures 41.36mm in length and has a maximum diameter of 11.88mm. The case has a short neck having a maximum diameter of 9.64mm. The primary purpose of the necked-down area is to contain the piston when fired. The case (with piston) weighs 107.3 grains. The primer is a Boxer-type, but the case cannot be reloaded.

The projectile is a mild steel cylinder (flat nose and base) measuring 28.4mm length and 7.63mm diameter. There is a 2mm brass band to engage the rifling at the forward portion of the projectile. The projectile weighs 155.4 grains, and it is estimated that the powder weighs in the vicinity of 3.5 grains.

Testing and Evaluation

Testing was performed on a military range. Weather conditions were ideal with a temperature of 83 degrees F (29 degrees C), relative humidity of 37%, and a station pressure of 676 mmHg. The altitude was 3,232 feet and there was no measurable wind.

On the range, we performed three separate tests: sound levels, velocity, and penetration of body armor and cinder blocks.

Sound Measurements

All measurements were done utilizing the protocol specified in Mil-Std-1474D. The meter, a Larson-Davis model 800B with a 1/4 inch LD-2530 pressure microphone, is a Type 1 precision sound meter in current certification. Prior to the start of measurement, calibration was checked with a recently re-certified Larson-Davis CA250 calibrator. Measurements were taken at the “reference” location of 1 meter to the left of the muzzle, 90 degrees to bore axis, and 1.6 meters above ground. Grass was not available, so measurements were made over compacted dirt.

In order, the individual shots of the 5-round string were measured at: 125.0, 124.5, 124.5, 123.8, and 125.0 dB. The overall average was 124.6 dB. First round “pop” is defined as to how much louder the first round measures compared to the average of the remaining rounds. While it was calculated, these are individual silenced cartridges, and the meaning of first round “pop” in this instance is not germane. The standard deviation was 0.44, indicating excellent shot-to-shot consistency.

Velocity Measurements

A Pact timer/chronograph was oriented with the skyscreens (spaced 24 inches) placed approximately two feet in front of the firing position. The skyscreens were approximately 1.6 meters above the ground so that we could obtain both sound and velocity measurements on the same cartridge. This was important to conserve ammunition due to its excessive cost and poor availability. In order, the velocity measurements were 625, 615, 624, 617, and 626 ft/sec for an average of 621 ft/sec. This calculates a muzzle kinetic energy of approximately 133 ft-lbs.

Terminal effects

We were unable to formulate ballistic gelatin in order to obtain information on the effectiveness on flesh. This will be the subject of a later study. However, information is available for comparable projectile weights and velocities. Based on the bullet weight of 155-grains and kinetic energy of 133 ft-lbs, the projectile certainly has enough energy to be lethal at reasonable close range. We did not shoot paper targets for accuracy. We felt that this was not necessary simply because the weapon system was intended and designed for exceptionally close ranges, probably less than 3 meters.

We did perform basic penetration tests. When fired at standard Kevlar Level-2 body armor, it just penetrated completely with the projectile being recoverable from the vest itself. While it will not be lethal through a vest, it will cause definite traumatic injury. It also penetrated a standard cinder block.

Proposed Future Tests

The performance of this cartridge in ballistic gelatin (with conventional photography as well as high speed video) will be of benefit in extrapolating and analyzing wound potential. While it is obvious that this has been used successfully operationally, we do not know of any autopsy reports.

In addition, we would like to perform high speed video analysis of the weapon cycling during firing for motion analysis of exactly how the floating chamber functions. To the best of our knowledge, this has not been performed. It is estimated that a frame rate of 3,000 frames/second should be adequate.

Summary and Conclusions

The PSS pistol and its specialized SP-4 captive piston silent cartridge is a highly specialized purpose weapon. Its suppressed sound pressure level of 124.d dB is in the vicinity of a suppressed .22 rimfire pistol and would definitely qualify as “Hollywood Quiet.” With a muzzle velocity of 621 feet/second and a 155-grain projectile, the kinetic energy of 133 foot-pounds is definitely lethal. The PSS pistol with the SP-4 captive piston silent ammunition was specifically designed for close-range covert elimination of targets. It is our opinion that this weapon/ammunition combination is well chosen for this task.

Born of necessity and requirements of the SOE, the Welrod silenced pistol was created to fulfill a need for an exceptionally quiet, easily concealed, and highly lethal assassination handgun. Designed around the standard European police cartridge, the 7.65×18 mm (.32ACP), the Welrod was a magazine fed, locked breech, manually loaded, integrally suppressed weapon for use at extremely close ranges. The weapon featured a ported barrel surrounded by wire mesh followed by a suppression chamber filled with stacked flat washer-type baffles and wipes with the wipes placed at intervals among the baffles. The original wipes were oiled leather, but it was found that the oil smoked too badly. Subsequent wipes were felt, cork, or a rubber material. The exit endcap was recessed and had a terminal wipe. The purpose of the recessed end cap was to allow space for the wipe to expand when the weapon was pressed against the target’s body, making the target a part of the suppression system.

There is some debate as to the origin of the name, “Welrod.” Originally referred to as the Hand Firing Device, J. David Truby offers two possible explanations of the nickname, Welrod. One is that it was developed near Wells, and in deference to the OSS and American slang of “rod” for gun, it became known as the “Welrod.” The other relates to England’s Welwyn Herts Laboratory where a number of clandestine weapons were developed for Britain’s SOE. The real name of the actual designer remains cloaked in British secrecy, even to this day. Actual production was performed under great secrecy at Birmingham Small Arms Company in Small Heath, Birmingham, UK.

Built primarily in caliber 7.65mm (Mk-2), a limited number of Welrods were also built in the standard 9mm military cartridge (Mk-1). Reports indicate that subjectively the 7.65mm version was considerably quieter than the 9mm. The Welrod has been built by a number of countries (including the United States), but the vast majority are British. Usually the weapon either had no markings whatsoever or perhaps carried a serial number. The reason for a paucity of markings was official deniability. The exception are the ones built in the United States, which had multiple lines of markings including description, model, caliber, actual manufacturer (and location) as well as stock number. (Dan’s note: The Brits consider this “Absolutely Brilliant!”; a supersecret clandestine weapon with all the info on it! Crazy Yanks!)

Although the Welrod originated in Great Britain, it was subsequently manufactured by several other countries, including the United States. The degree of suppression has been described as essentially totally silent by both users and observers.

In our latest expedition to the United Kingdom, the SAR Expeditionary Force recently had the opportunity to not only fire two original Welrod pistols but to also do accurate sound measurements. To the best of our knowledge, no accurate objective sound pressure level measurements of the Welrod were available or had been performed with modern MIL-SPEC sound measuring equipment.

We are deeply indebted to Gregory Felton of Law Enforcement International, Ltd. for providing the weapons, ammunition, sound meter, and range facilities outside of London for the testing.

Although weekend London traffic is bad, weekday traffic is abominable. It is even more difficult for Yanks in that we had to get used to driving on the other side of the road. Arriving somewhat later than expected at the LEI offices, we chose a number of weapons for testing, including two different Welrod pistols in caliber 7.65 mm. Both were of British origin and neither had any markings or serial numbers, which is typical. One was in absolute original condition, although it had been fired previously and the wipes were both used and brittle. The other had new wipes installed. LEI has a Larson-Davis Laboratories 800B sound level meter with the correct LDL 2530 microphone and a LDL CA-250 calibrator. The meter also included a RS-232 interface, enabling us to drive the meter with a laptop computer to rapidly acquire, record, and analyze the data.

After packing the car, we were more than happy to let Greg Felton navigate London traffic and head for the range. Although the day started sunny, the forecast was for heavy rain and high winds. We left under threatening skies, and once on the motorway, Greg treated us to an example of how to get to the range in minimal time. Shooting in the United Kingdom is far different than in the US, and shooting can only be performed at a registered range with a written log kept of calibers and shots fired. The range LEI had reserved was privately owned and was located on a farm about an hour and a half drive from London, even at speeds of 125 mph. Originally part of a WW-II Allied air strip, the range had been used to test the machine guns on Spitfire aircraft. The remains of the airstrip were subsequently returned to farmland with a current crop of rye. The owner, a shooter and foxhunter himself, maintained the range.

Upon arriving and posting the required signs along the road and warning red flags, we set up the meter, calibrated it, and prepared for shooting. Although breezy and threatening rain, the windscreen on the microphone prevented wind noise contamination of the readings. The temperature was 20° C (70° F), the humidity approximately 80%, and the barometric pressure 740 mmHg. Not having a test stand similar to the one I use in Idaho or what Al Paulson uses, we improvised using a 1-meter blue ribbon for spacing the muzzle from the microphone, which was attached to a camera tripod. I operated the meter and laptop, Greg Felton was the shooter, and Dan Shea carefully checked position and alignment prior to each shot. Dan also was the official photographer.

The protocol used was that described in the August 2000 issue of Small Arms Review, “Firearms Sound Measurement Techniques” and met the requirements of MIL-STD-1474C as applied to small arms fire. We made all measurements with the microphone located 1 meter to the left of the muzzle at right angles to the bore axis. Although normal testing protocol is for averaging a string of 10 shots, we abbreviated the string to five shots. This was primarily because of the rarity and age of the weapons. All of the measurements were made in a 15-minute period.

There is no such thing as a non-suppressed Welrod, and for non-suppressed measurement data, we used a Walther PP pistol in 7.65mm with a barrel 1/2 inch longer than normal. We subsequently used this same weapon to measure the weapon’s LEI manufactured suppressor, the subject of another article. The average of five shots non-suppressed was 156.8 dB with less than 0.2 dB variation between the shots.

Following non-suppressed measurements of the cartridge, we tested the original Welrod. This weapon, almost 50 years old, dated to World War II. It was completely original (including the wipes and internal meshes) and had seen considerable usage. The wipes in the front end cap were brittle and fairly well shot out, and I suspect they were worn enough that the projectile didn’t even touch the wipes. Measurements were not quite as fast as with a semi-automatic weapon, because the bolt had to be manually cycled after each shot. Although no hearing protection was required and the sound levels were not uncomfortable, the degree of suppression subjectively was less than what one would expect. Metering confirmed this impression with the average of five shots being 142.4 dB, a reduction of only 14.4 dB as compared to the non-suppressed Walther reference weapon. In spite of the weapon being well used and well worn, there was virtually no first round pop and little shot-to-shot variation.

Our next test weapon was Greg’s other Welrod, also caliber 7.65mm. Although this weapon dated to the same mid-1940s period, it had been restored to original condition with new wipes that occluded the bore passage completely, Greg assured us that all the internal parts had been refurbished in a similar manner. The difference was dramatic, and subjectively this Welrod was “Hollywood quiet.” The actual objective sound measurements showed an average of five rounds to have a sound level of 122.8 dB with no first round pop and with no shot more than 1 dB from the average. Compared to the non-suppressed Walther, the reduction was 34.2 dB. The weapon sounded quieter than a CO2 pellet pistol!

There were several other early sound measurements performed in the United States, including at Aberdeen in 1966 and by Frankfort Arsenal in 1968. To the best of my knowledge, these did not include non-suppressed measurements. Although the best available at the time, the equipment used would not meet current specifications required by MIL-STD-1474C. The Frankfort Arsenal measurement location was 5 meters to the side of the muzzle while the current preferred location is 1 meter to the left of the muzzle. I do not know the Aberdeen test protocol. Most of the sound pressure levels were not totally believable, even when calculating the differences due to differing microphone locations. Undoubtedly this was a function of the available measuring equipment (including excessive meter rise time).

Although the sound meter as an objective measurement is an important benchmark, it does not tell the entire story. There are a number of air (pellet) pistols with similar sound levels and some integrally suppressed .22 rimfire pistols with a slightly lower sound level. The subjective evaluation of the Welrod is that it makes less noise than these other weapons. Part of the reason is the locked breech. Although left-of-muzzle measurements of the .22-rimfire weapons may meter a lower sound level, subjectively they are louder due to right-hand ejection port noise. Further, the Welrod, with its wipes, significantly changes the sound characteristic with elimination of virtually all the higher frequency sounds. The sound of the Welrod being fired in a quiet location is almost imperceptible at 15 feet. In a noisy environment and with the muzzle in actual contact with the intended target, it would be inaudible even to the operator.

In the opinion of the members of the SAR Expeditionary Force, the Welrod achieved its design goals as an easily concealed, lethal assassination weapon. We can easily understand why it is still classified as an operational weapon even 60 years after its inception.

We are deeply indebted to Greg Felton and Law Enforcement International, Ltd. of London, UK for providing us the weapons, facilities, time, and great companionship for these tests.

References:

Dater, Philip, “Sound Measurement Techniques,” Small Arms Review, V. 3 No. 11, Aug 2000
Truby, J. David, “The Ugliest 60 Year Old Gun I Ever Saw,” Small Arms Review, V. 2 No. 4, Jan 1999
Truby, J. David, Silencers, Snipers & Assassins, Palladin Press, 1972

By Matt Smith

SAR: Recount for us how you got started in the business.

PHIL: It started in 1976, when I purchased a couple of Military Armament Corporation suppressors. One of the suppressers was on a Ruger MK 1 pistol, and after a brick of ammunition, it was not quiet any more. After the manufacturer refused to service the suppressor, I took it apart myself and figured out a way to repack it with copper scouring pads, in place of the original screen discs. In 1978, I got my first manufacturers license as Automatic Weapons Company in New Mexico, and started producing an improved suppressed Ruger pistol as well as other types of suppressors. In 1981, Peter Kokalis came out and spent a couple days with me and wrote an article for Soldier of Fortune Magazine, which did me an amazing amount of good. In 1983, one of my dealers, Lynn McWilliams, in Friendswood, Texas, approached me and we worked out an arrangement, where he would take care of the manufacturing and I would do the research and development. In about 1989, we went our separate ways as friends. In 1985, Lynn’s business became known as AWC Systems Technology, and is now located in Phoenix. I moved to Boise in 1991. In 1993, Jim Ryan and Mark Weiss of JR Customs and I formed Gemtech with Greg Latka of GSL Technologies coming on as a major partner in early 1994. We worked together for several years, but in 1998, we decided to split up. Greg and I kept Gemtech while Jim and Mark formed Tactical Ordnance. A year ago, I hired Kel Whelan to do our marketing, sales, and office management. Although we have always had steady growth, in the last four to five months business has really boomed. (Dan’s Note: Phil, is “Boomed” really the right term to use for a suppressor business?)

SAR: How would you characterize your customer base?

PHIL: We’ve been growing each year, since being formed. We’ve been getting a lot more law enforcement usage of our products, while the civilian market has increased with moderate growth. Our products have been exported with many going to the Asian rim, and have sold to the U.S. Military in sole source procurements. Currently, our products are being used by our military in Afghanistan and Bosnia. Our customer base is about sixty-five percent civilian, thirty percent law enforcement, and roughly five percent military.

SAR: Are any of your old designs still in demand today?

PHIL: Yes, the SG-9 integral suppressor for the Sten MK II and Smith and Wesson 76, which I designed in 1976 is still in high demand. I build thirty or forty of these a year in my spare time, and there is still a waiting list.

SAR: What are your best selling suppressors?

PHIL: Currently, they are the M4-96D quick disconnect .223 suppressor, the 9mm Raptor for the MP-5, and the .22 LR screw-on Outback suppressor.

SAR: Who are some of the other suppressor designers that you think highly of?

PHIL: I’ve always had a lot of respect for Doug Olson, who worked for years with Mickey Finn, and then with Lynn McWilliams, and currently for Reed Knight. He’s a very innovative man. Reed Knight is well known for his designs and makes excellent products, although they are expensive. Lynn McWilliams at AWC has historically been good at business and marketing, and has been able to promote a good product. Of the newer designers, I’m impressed with Joe Gaddini of SWR, who is an independent thinker. The men that I respect are those who think on their own. Any monkey can take someone’s existing products, cut them open and clone them, or stuff dimpled washers into a tube and call it a suppressor. Doug Melton of SRT Arms I respect, as he is an independent thinker and not a copycat.

SAR: What are your thoughts about research and development?

PHIL: Research and development is something you have to devote a lot of money and time to. First, you have to see a need for a new product or product improvement. Typically, on a suppressor, this means that it is physically smaller or more efficient. We strive for both of these goals. One of our R&D success stories is the M4-96D suppressor, which was developed in five weeks. Jim and Mark in Washington did all the paper work for the Navy request and Greg designed the mount and several ideas for baffles, which he sent to me for testing. I tested various prototypes with a meter over a ten-day period. We started off with a 24 dB reduction and ended up with a 32.5 dB reduction suppressor in the same size envelope. We conducted the required testing and ended up with a suppressor that exceeded the Navy’s requirements. Unfortunately, we did not win the Navy contract, but we did develop one of our best sellers in a short amount of time.

SAR: Do you have any new products you can tell us about?

PHIL: Currently, we have a new .223 suppressor that we are calling the Piranha M4-02. It has been designed for law enforcement entry teams, and priced under $500. The dimensions are 1-3/8’s inches in diameter, 6-1/4 inches long, screws on the barrel, and does 29 dB reduction on an 11 and 1/2 inch upper. We also have a new device we call the Linear Inertial Decoupler. This started with an idea from Joe Gaddini, which Greg modified. It works like a Nielson device, except there is no piston to drive the barrel backwards. This eliminates damage to the firearm, which occasionally takes place when the Nielson Device is not tuned to the specific model weapon. Our Decoupler isolates the mass of the suppressor from the barrel to allow the barrel to start the unlocking process. This device is so successful that it can even be used on a Glock 26 or 19 with our suppressor for flawless cycling. A patent is being applied for on this new innovation, which is currently available on our Vortex 9 suppressor and will be available on a .45 suppressor for the HK and other pistols.

SAR: Do you also have another version of the M4-96D for the belt fed M249 machinegun?

PHIL: Yes, it is the M4-96E. This is a ruggedized version of the D and incorporates laser welding of the baffle stack to maintain rotational orientation perfectly. One of the problems with prolonged firing of the M249 is heat generation. Running a 250 round belt with a suppressor in place develops a core temperature in the suppressor of 1200 degrees F, with the barrel temperature around 1000 degrees F. These temperatures cause ammunition to come apart and deposit copper residue inside the suppressor. Firing full belts is certainly possible with a suppressor, but will severely limit the life span of the suppressor. We will only sell this suppressor to the military, where fire discipline requires shooting in bursts, rather than complete belts at a time. We also have a new .223 suppressor we call the M4-96X for export, which will mount on any NATO standard flash hider. The mount is licensed from abroad, for the military and export only. Our .308 TPRS has been undergoing a lot of changes over the last two years with the revision of the baffle stack, to solve some accuracy problems. It is now also capable of handling .300 Win Mag with no problem. It is a frequency shift unit that places much of the sound into the higher frequency range outside of human hearing. The suppressor is also extremely quiet when shot with EBR subsonic ammunition, which we heartily endorse. The Black Hills subsonic .308 is also a solid performer.

SAR: Has the Internet been beneficial to your business?

PHIL: It’s of marginal value. The discussion boards seem to generate very little business for us, but are a value to the general public. We have a web site (www.gem-tech.com), which acts as a convenient international catalog. A number of law enforcement agencies have found and contacted us through our web site.

SAR: How have your printed ads in SAR done for you?

PHIL: We have gotten really good response to all of our ads in SAR. The people who read SAR are almost all potential customers for us, and this is what we strive for when we advertise. We will continue to support SAR as we have in the past, and encourage all of our customers to do the same.

SAR: Thanks for sharing your thoughts with us.

PHIL: You’re welcome.

Gemtech
P.O. Box 140618
Boise, ID 83714
PH (208) 939-7222
FAX (208) 939-7804