This is just about the only place you’ll learn about the history, plus insights into the technology, testing protocols and where they came from, hearing loss, and the science of firearms sound.

The course is $495- call Phoenix Defence at 702-208-9735 or email at info@phoenixdefence.com

Silencer History, Technology & Testing Course

• Date: September 19-20, 2023
• Location: Boise, ID
• Instructor: Philip H. Dater, MD
• Cost: $495.00
• Course Number: PD-SUP-T

Syllabus:

DAY 1: Classroom

• Part 1: Introduction, Hearing Damage, & Usage (71 slides)
• Part 2: Suppressor Designs (124 slides)
• Part 3: Sound Measuring (78 slides)

On the second day, participants will be provided with a handout (as a DVD) of the slides used in the presentation, results of prior testing, considerable reference material (as PDF files), and a number of fun high-speed videos.

DAY 2: Classroom

• Part 4: Improvised Silencers (51 slides)
• Part 5: Design Process, Testing & Longevity (112 slides)
• Part 6: Mounting, Stability, Damage, and Goofs (71 slides)

BONUS (on Handout DVD, not covered in class): The Early Pioneers

•    Hiram P. Maxim
•    Mitchell WerBell
•    Charles A. (“Mickey”) Finn
•    C. Reed Knight, Jr.
•    Douglas Olson
•    Jonathan Arthur Ciener

With the popularity of firearms suppressors at an all-time high and the Hearing Protection Act hopefully gaining momentum in Congress, it is an appropriate time to ask: When did suppressors first emerge and why did they disappear? At the turn of the 20th century there was an explosion of silencer designs and by 1912 the U.S. Army had become interested in their military applications, but the Great Depression and the 1934 National Firearms Act saw sales decline.

The first viable firearm suppressors appeared at the turn of the 20th century with a series of patents between 1909 and 1920. In 1895, Hiram Percy Maxim, son of Sir Hiram Maxim—inventor of the machine gun—established an engineering company. Initially, Maxim’s company was focused on the burgeoning automobile market. It was not until 1905 that Maxim began developing a series of designs to moderate sound. To begin with, he experimented with valves, vents and bypass devices. He eventually finalized his basic idea and developed a series of practical suppressors; these were sold by the Maxim Silent Firearms Company, which later became the Maxim Silencer Company.

In later years, Maxim claimed that he came up with the idea after taking a bath. As he watched the water drain out of the bath he noted that it spiralled as it formed a whirlpool at the drain. He believed that the propellant gases leaving a firearm’s muzzle could also be whirled to create a vortex, thereby slowing them sufficiently to prevent them making a noise as they left the muzzle.

Maxim experimented with his idea and created his first silencer, which used an offset chamber and valve to trap and swirl the muzzle gases in an effort to slow their travel. Maxim’s results with this design were encouraging, but the design needed further refinement.

In June 1908, he filed his patent for an “improvement in Silent Firearms.” Granted in March 1909, this design used curved vanes or blades to create a series of miniature vortices to capture and slow the muzzle gases.

The Model 1909 Maxim silencer was not produced in great numbers and the vortices caused the suppressor to heat up rapidly. While the Model 1909 could reduce a .22LR pistol’s report by up to 30 decibels, the curved internal vanes proved expensive to manufacture. In October and November 1908, Maxim filed two more patents to protect an improvement on his earlier design. This new design became the Model 1910; it still relied on Maxim’s gas vortex theory but had a simplified vane arrangement. The Model 1910 also moved away from having a centrally aligned internal channel and instead used an offset or eccentric design. This had the added benefit of not obstructing the weapon’s sights.

The majority of rifles of the day did not have threaded barrels, so Maxim developed a coupling device that was placed over the muzzle and offered an external thread. One of the main drawbacks of the Model 1910 was that it could not be disassembled for cleaning. Instead Maxim sales brochures recommended that hot water should be run through the silencer’s channel for 30 minutes.

The Model 1910 proved commercially successful and was offered in a number of calibers from .22 up to .45 caliber. The thinner Model 1910 was less effective than the earlier 1909, but when fitted to a .22LR pistol the Model 1910 could still reduce the weapon’s report by up to 25 decibels. Both the 1909 and 1910 models proved to be fairly robust and moderately effective suppressors.

A second variant of the Model 1910 did not use the vortex-creating vanes, instead it used straight baffles (which the patent described as “spreaders”), as Maxim increasingly understood that the most important element of the suppressor was its ability to slow the movement of the muzzle gases.

Maxim’s book Experiences with the Maxim Silencer compiled letters from sportsmen and hunters who had used his silencer. In the book’s foreword, Maxim explained that he developed his system in order to “meet my personal desire to enjoy target practice without creating a disturbance. I have always loved to shoot, but I never thoroughly enjoyed it when I knew the noise was annoying other people.” This continues to be a key argument for suppressor usage today.

The Maxim Silencer Company sold the silencers via mail order, shipping them in cardboard tubes. A .22 caliber silencer cost $5 while larger-caliber silencers cost $7. Maxim’s silencers were expensive items; when adjusted for inflation, these prices respectively equate to approximately $120 and $165.

The adventurer president, Theodore Roosevelt, suppressed his .30-30 Winchester Model 1894 with a Maxim silencer. Roosevelt used his rifle for small game hunting on his Long Island property. Maxim’s commercial silencers sold well during the 1910s and 1920s with hunters, target shooters and plinkers all purchasing silencers. Maxim even sold indoor target backstop boxes that could be filled with sand and used in conjunction with a silencer to shoot indoors.

Maxim’s Rivals

With the success of Maxim’s silencers, a number of rival companies began selling their own designs. The early 1910s saw a flurry of designs patented, which included the following: James Stinson’s “Gun Muffler”; the George Childress hemispherical expansion chamber silencer; Charles H. Kenney’s 1910 silencer, which had a large pre-expansion chamber; and Andy Shipley’s 1910 patent was one of the first to suggest porting the firearm’s barrel. Others included Major Anthony Fiala’s spiral baffle silencer; Harry Craven’s early shotgun silencer; Eugene Thurler’s 1911 patent that described a bayonet-style attachment system and used deflecting cones; Herbert Moore’s gas trap; and R.M. Towson’s “Recoil Neutralizer and Muffler,” which was little more than an unconventional muzzle brake for both small arms and artillery.

Among the multitude of rival designers, Maxim’s most competent competitor was Robert A. Moore, who patented his first silencer design in 1910. Developed for large caliber hunting and military rifles, Moore’s design included a large gas chamber that sat beneath the rifle’s muzzle. The muzzle gases were supposed to be deflected by concave surfaces down into the silencer, which had a number of partitioned chambers. The sides of the silencer were ported with vents to allow cool air to rush into the casing and, theoretically, cool the gases. The entrance to the silencer’s chambers also had a movable divider that was opened by the force of the gases and closed to prevent their escape.

Moore’s silencer had a number of interesting features. For instance, it used a rifle’s bayonet lug as an attachment point and also had removable side plates to allow cleaning of the silencer’s interior—both practical features for military use. Moore’s first design, however, did not go into production and he began work on a second model.

In 1912, Moore patented a more sophisticated silencer, moving away from the ported chamber concept. Instead, Moore’s new design first trapped the gases in a large expansion chamber, which again deflected some of the gases into a chamber beneath the muzzle. The silencer also had an additional series of curved baffles in front of the muzzle with expansion chambers below them. The elegant curves of the chamber partitions were designed, much like Maxim’s, to impart spin and create vortices to slow the travel of the gases. Moore’s patent explained that the curved baffles created two separate sets of vortices that slowed one another down when they intersected. The result was a silencer which attempted to slow the travel of gases with both expansion chambers and vortex-creating baffles.

Ingeniously, Moore designed his baffle system to be removable to facilitate cleaning and maintenance. Moore’s 1912 silencer also used the rifle’s bayonet lug as an attachment point and also provided another lug on the silencer’s housing to allow a soldier to attach a bayonet even while using the silencer. There were, however, some issues with fixing a bayonet while using the silencer. The additional length of the silencer combined with the bayonet meant the rifle’s balance was adversely affected, making it muzzle-heavy and difficult to fire accurately off-hand. During trials of the rifle it was noted by Ordnance Corps evaluating officers that the silencer’s rounded muzzle allowed the bayonet ring to slip under recoil.

The Military Maxim and the U.S. Silencer Trial

In 1912, with commercial growth slowing, Maxim turned his attention to the Military market and began designing a silencer that could moderate the report of a Springfield M1903. The Ordnance Corps had tested Maxim’s first silencer in 1909. Colonel S.E. Blunt, the commanding officer of the Springfield Armory, reported that the silencer eliminated approximately 66% of the noise and 67% of the recoil normally made when a rifle was fired.

The Maxim Silencer Company developed the Model 1912 and subsequently the improved Model 15, which Maxim christened the “Government Silencer.” Encouraged by the early military interest, Maxim envisioned a military silencer being useful in roles such as sniping, guard harassment and marksmanship training. He believed that the increasing number of inexperienced shooters from cities joining the U.S. military was struggling to master the .30-06 M1903 because of its loud report and recoil. Maxim felt that using a silencer would prevent recruits being intimidated by their rifle and help them to learn the fundamentals of marksmanship faster.

The U.S. Army decided to test both Moore’s and Maxim’s suppressors. When they compared the two rival designs, there was little difference between them with regard to the reduction of sound, recoil and flash. However, the Springfield Armory’s report in July 1912 found that the Moore silencer was more accurate and had a better attachment system. The Maxim silencer, on the other hand, was more durable and could withstand more prolonged rapid fire. Army Ordnance recommended the purchase of 100 of both silencers for field trials with two silencers to be issued per company for use by sharpshooters in conjunction with two star-gauge (accurate barreled) rifles and the M1908 and M1913 Musket Sights. This was not the large-scale contract that Maxim had hoped for, however, the funding was not available and the idea behind the silencers’ use was not fully embraced by the military.

The U.S. military’s first deployment of silencers came in 1916, when General John Pershing’s Mexican expedition against Pancho Villa included a squad of snipers apparently armed with silenced M1903s, however, little is known about their use in the field.

Maxim’s military silencers shipped around the world, with orders from Mexico, South America, China, Japan, Britain, France, Belgium, Russia and Germany. One pre-war Maxim advert boasted that the design had been approved by the German military. During the First World War, both the British and Germans deployed snipers equipped with Maxim silencers in small numbers. Some American troops deployed to Europe were also equipped with silencers, which were often paired with the M1913 Warner & Swasey “Musket Sight.” While these rifles could not prevent the supersonic crack that occurred downrange, they were able to mitigate muzzle flash and the rifle’s report. In 1917–18, a plan to deploy silencers with rifles with accurate star-gauged barrels was developed. An order for 9,100 was placed. Although part of this order was fulfilled before the end of the war, the exact number of silencer-equipped rifles manufactured remains unknown. After the war, these rifles were offered for sale through the Civilian Marksmanship programme in 1920, others were given to National Guard units for training purposes, and the remainder were declared obsolete in March 1925.

While the First World War offered a brief boom in sales of silencers this did not last, and Maxim’s company continued to diversify after the war. The Maxim Silencer Company manufactured not only firearm silencers but also sound-moderating devices for everything from automobiles to naval engines; from plant machinery to building silencers which were fitted to heating and air conditioning systems. Similarly, Moore, like Maxim, also later developed silencers for automobiles, filing a patent for an Exhaust Muffler in 1930.

The company began to move away from firearms silencers in 1925, instead concentrating on industrial and automotive sound moderators. Hiram Percy Maxim died in 1936, and his son took over the company. Although no longer family-owned, the company continues to specialize in industrial sound-moderating technology.

The National Firearms Act and the Decline in Civilian Silencers

The civilian market for firearms silencers was dealt a severe blow in 1934, when the National Firearms Act was introduced in response to the rise of organized and violent crime, with gangsters like John Dillinger and Baby Face Nelson increasingly using automatic weapons. While the use of silencers by gangsters was minimal, they were included in the National Firearms Act, which required a tax payment and registration of their ownership with (what later became) the Bureau of Alcohol, Tobacco, Firearms and Explosives. While this was not a ban on suppressors, the prohibitively expensive $200.00 tax stamp (approximately $3,500 today) placed on them effectively killed the market. Interestingly, during the National Firearms Act’s passage through Congress, silencers were almost never mentioned during the debates or committee meetings. It is often said that they were included at the request of the Department of the Interior to prohibit poaching or as a personal preference of the Attorney General Homer S. Cummings; however, the true reason for their inclusion in the act remains unknown.

The result of the National Firearms Act was that all silencers had to be registered and that pre-existing unregistered silencers were subsequently illegal to own. This has led to the destruction of many early examples to avoid Federal penalties.

It was not until the outbreak of World War Two that silencer technology would be revisited by the military. The technology was not adopted for the training uses envisaged by Maxim, but for specialized, clandestine roles that required quiet, efficient and deadly weapons.

Just a few examples of the .22 caliber firearms available for suppressor use.

By Frank Iannamico

Sound suppressors, also known as “silencers” by ATF and Hollywood or “cans” by enthusiasts, have become extremely popular in recent years. Many manufacturers of rifles and pistols now offer models with factory threaded barrels. There have also been a growing number of companies entering into the suppressor business. The suppressor competition is good news for the end user as the technology will continue to improve.
Modern suppressors are now smaller, lighter and quieter than those produced just a few years ago. The most innovative step forward was the introduction of the wipeless suppressor. During the 1960s there were very few U.S. companies making sound suppressors; one of the best known was Sionics (acronym for Studies In the Operational Negation of Insurgents and Counter-Subversion) operating out of Atlanta, Georgia. The Sionics Company, run by Mitch WerBell, specialized in the manufacture of covert products and their primary product was sound suppressors. Sionics’ customers were the military and governments, both foreign and domestic and offered sound suppressors for a number of military rifles and pistols.
In the late 1960s, Sionics began the manufacture of Gordon Ingram’s Model 10 submachine gun, and the company name was changed to the Military Armament Corporation. The sound suppressors designed and produced for the Model 10 was a two-stage design using metal eyelets in the first stage, right and left spirals and wipes in the second stage. The suppressors were made in .380 caliber, 9mm, and .45 ACP. The MAC suppressors were large and heavy. As the suppressors were used they became progressively louder as the rubber wipes deteriorated and become less efficient. After approximately 200 rounds the wipes had to be replaced.
After The Military Armament Corporation went out of business, the Sionics/MAC suppressor designs continued to be manufactured by RPB and a few years later by SWD. It was at this point in time the suppressors became much more available to the general public, where permitted by law. A number were sold, but they were not especially popular, primarily because of the registration process, and the transfer tax that was usually more than twice the cost of the suppressor.
During the 1980s unregistered suppressor tubes and baffles were offered for sale, but advertised separately. Tubes were available from one company and the internal components from another, often the same company operating under different names. Similar sales were being made at gun shows from separate tables, all perfectly legal at the time. Before long, law enforcement officials were reporting a large number of illegal suppressors being seized. These types of sales strategies are what led to current laws banning the possession of spare suppressor parts.
Today, those in the market for a sound suppressor have a lot of options and many models available for them to consider. The most popular are those designed for .22 caliber rimfire rifles and pistols. This article is to introduce the reader to some of the more popular host firearms for mounting a .22 caliber suppressor.

Ruger 10/22 Rifle

The Ruger semiautomatic .22 caliber rifle introduced in 1964, celebrated its 50th year of production in 2014. The Ruger 10/22 rifle is one of the most popular .22 caliber firearms ever made with more than 6 million sold since its introduction.
The Ruger 10/22 rifle has proven to be a very reliable semiautomatic rifle. Since its introduction there have been several minor changes in its design and construction materials. As delivered from the factory the 10/22 rifle is fed from a 10-round rotary magazine.
The Ruger 10/22 rifle is currently available in seven different models. For those interested in mounting a suppressor, the obvious choice would be the 10/22 Tactical Model 1261 that comes from the factory with a 1/2-28 threaded 16.12-inch long barrel, synthetic stock, extended magazine release, and accessory rail for mounting optical devices. The rifle does not have conventional sights.
If you have an older model of the Ruger 10/22 there is a very large accessory aftermarket for upgrading the rifle. Available accessories include large capacity magazines, target and tactical stocks, threaded barrels and much more. The barrel of the 10/22 can be easily removed to be threaded for a suppressor or replaced with a new threaded one.

Savage Mark II FV-SR Rifle

When firing a suppressed semiautomatic rifle or pistol, sound is generated from several sources: the muzzle of the weapon, the ejection port, the action cycling and the bullet impacting the target. Other than the muzzle report, many of these sounds are not normally heard when firing unsuppressed firearms.
Firing a suppressed bolt-action rifle eliminates the sound generated from the ejection port and the semiautomatic action cycling, until of course the rifle’s bolt-action is cycled by hand after the shot, making a bolt-action rifle the best choice for the ultimate in quiet. A suppressed .22 rimfire caliber bolt-action rifle can be phenomenally stealthy.
The bolt-action Savage Mark II FV-SR has been a very popular choice for mounting a suppressor. The rifle comes from the factory fitted with a 16.5-inch 1/2-28 threaded heavy-profile, free-floating, fluted barrel, oversize bolt handle, Picatinny style optics rail, the adjustable Savage factory AccuTrigger, black synthetic stock and 5 or 10-round detachable magazine. The barrel comes with a knurled thread protector the same diameter as the heavy barrel.
When fitted with a red dot or telescopic sight the Savage Mark II FV-SR can be an accurate rifle.
One problem encountered was with the magazine. The metal body is pressed together and after reloading the magazine a few times the sides spread apart and the cartridges would not stay in the magazine. An internet inquiry revealed this to be a common problem.

Walther P22

The Walther P22 has been an inexpensive and popular .22 caliber pistol for mounting a suppressor. The pistol features a double-action first shot, and single action for subsequent shots. The pistol’s frame is made of polymer with stamped steel internal components; the slide is made from a zinc alloy. The barrel, recoil spring guide, extractor and ejector are made of steel. The magazine is constructed of stainless steel with a polymer follower and bump pad. An interchangeable backstrap allows the grip to be customized to the shooter’s hand. Sights consist of a polymer ramp front sight with a white dot pressed into the slide and a polymer rear sight adjustable for windage with two white dots. Two additional front sights come with the pistol to adjust elevation. The P22 features an ambidextrous magazine release located at the back of the trigger guard. Under the frame is a rail for the mounting accessories, including a factory laser designed specifically for the P22. The P22 is available in several variations as well as quite a few color options.

SIG Mosquito

The .22 caliber SIG Sauer Mosquito is a medium-size, double-action; semiautomatic pistol with an appearance, with the exception of its slide-mounted safety, and operation similar to that of the SIG Sauer P226 model. For the SAR evaluation the Mosquito “Silencer” TB model was tested. The silencer model is a bit of a misleading name. While the pistol does have an extended, threaded barrel, an aftermarket adapter is still required for attaching a suppressor with standard 1/2-28 threads.
The Mosquito’s slide is made of an aluminum-zinc alloy. Mounted on the slide are a blade front sight and adjustable rear, both with yellow-green inserts. The sights are tall enough to be visible with most brands of .22 suppressors on the barrel. The Mosquito has a polymer frame and has an integrated Picatinny rail for a light or accessory. The pistol has a slide-mounted, ambidextrous, manual safety switch located below the rear sight. A second safety feature requires the magazine to be in place before the pistol will fire. For storage or security purposes there an integral, key-operated safety lock located at the base of the grip. Located just forward of the slide catch lever is a decocking lever. Magazine capacity is 10 rounds. The fixed steel barrel is blued with a length of 4.9-inches. The Mosquito is available in several color combinations.
There have been a few reliability problems reported in early manufacture Mosquito pistols, but the problem seems to have been addressed. Three different pistols were tested with only one or two failures to feed using a variety of .22 ammunition brands. There was an ongoing reliability problem with Aguila Subsonic ammunition, but there was flawless reliability with CCI Standard Velocity, which has traditionally been the most popular .22 ammo for suppressor use. The Mosquito comes with two recoil springs, one for high-speed loads and another for standard ammunition. The pistol comes from the factory fitted with the high-speed spring. Also included is a wrench designed to remove the factory thread protector, a set of shorter sights and a safety locking key.
The SIG Mosquito has the look and feel of a center fire pistol. Like some other .22 caliber firearms it can be ammunition sensitive; some trial and error may be required to find ammunition that is compatible with any particular pistol.

Ruger Mark II

The Ruger series of single-action, semiautomatic .22 caliber pistols are very popular and have been in continuous production for over 65 years. Ruger’s first semiautomatic pistol was the Standard, made from 1949 to 1982. The original design was replaced by the new Mark II model in 1982. The MK II featured a slide stop that held the slide open on the last round, and was available in stainless steel. Other MK II variations include the Target models with heavier barrels and adjustable sights, and the 22/45 models, with a polymer frame having the same grip-angle as a 1911 pistol. The MK II was replaced by the Mark III in 2004. The Mark III introduced a number of new safety features: a visible loaded chamber indicator, a magazine disconnect that prevents the pistol from being fired with the magazine removed and an internal safety lock that locks the pistol in the “safe” position with a key. Other non-liability features include tapered bolt ears, contoured ejection port, and relocated magazine release.
Unlike many of the newer .22 caliber pistols, the Ruger Mark pistols (except for the polymer frame 22/45 Model) have a steel frame and slide. The magazines also are made of steel have a 10-round capacity.
Due in part to its popularity and many years in production there is a large choice of aftermarket parts and accessories for the Ruger line.
Ruger .22 pistols are available in a large number of configurations and barrel options to include the Standard, Target, Hunter and Competition models. Ruger currently offers their SR-22 and the 22/45 .22 caliber pistols with factory threaded 1/2-28 barrels.

Colt/Walther 1911A1

John Browning’s original 1911 pistol design has been one of the most popular handguns in the U.S. for a long time. Since its introduction, it has become available in many configurations and manufactured by an ever-growing number of companies. The basic 1911 has been offered in a number of popular calibers including the original .45 ACP, .38 Super, 9mm and .22 rimfire. Recently there have been a rather large number of dedicated .22 caliber variants introduced to the market.
Walther/Umarex manufactures a full-size .22 caliber 1911 single-action pistol under license from Colt in Germany. The pistol was designed and manufactured according to the original Colt plans and at a 1:1 scale and accepts many regular 1911 accessories, this alone makes this gun appealing to many.
The Colt/Walther Government 1911A1 is chambered in .22LR with a magazine capacity of 12 rounds. It weighs 2.25 pounds empty, and it has an aluminum slide and a zinc alloy frame. Like the standard 1911, the .22 variant has both manual thumb and grip safeties. The standard 1911 style sights this comes equipped with should be tall enough to be usable with most modern .22 suppressors on the market. Disassembly is similar to a standard 1911. The .22 replica has a M8x.75mm 5.5 inch threaded barrel. While this barrel does not extend past the slide, it has a thread protector that can be removed to expose the metric muzzle threads. This allows the user to attach a readily available 1/2-28 thread adapter for attaching a suppressor.
Many enthusiasts have voiced concern about the use of the zinc alloy used in many of the .22 pistols available today, with visions of the old fragile “pot metal” of old. Unlike .22 caliber pistols designed exclusively for that caliber, when designing a replica of a modern center-fire pistol gun in .22 caliber, the slide must be made from a light-weight alloy material in order for the pistol to function with the low power round. Walther has stated that the material they use is a sophisticated zinc alloy that they selected for its durability, and the company has stated that they do not anticipate any issues with the material.

GSG 1911

The German Sports Guns (GSG) 1911 designed .22 caliber single-action pistol is another copy of the famous 1911A1 pistol. All the controls are pretty much the same as any government issue. The gun weighs 34 ounces, which is just a few ounces lighter than a typical .45 1911, thus it feels like a “real” 1911, except for the stiff grip safety that you must consciously depress. Some of the early production of the GSG 1911 had some reliability issues. However this has been acknowledged by the manufacturer who offers an upgrade package that consists of a new recoil spring and guide rod assembly. The pistol tested had a very sluggish slide that often did not have enough forward velocity to strip a round from the magazine. The problem was easily fixed with the new spring and guide rod factory upgrade.
The GSG 1911 comes with a number of so-called “enhanced” features that used to be only found on custom 1911s including ambidextrous safety, beavertail grip safety, extended trigger with adjustable “commander” style hammer, and extended magazine catch. The pistol slide remains open on an empty magazine, and the magazine release and slide stop function are the same as a 1911. The slide of the GSG-1911 is aluminum and the frame/receiver body of the pistol is a Zinc alloy. The barrel is fixed in position. A fair amount of parts of the GSG 1911 are interchangeable with a standard 1911 pistol.
Takedown for cleaning the GSG 1911 was a little more complicated than a .45 caliber model with an extra screw that has to be removed to disassemble the pistol.

Browning Buck Mark

The Buck Mark pistol is one of the most proven 22 rimfire designs available today. The Buck Mark has been in continuous production since 1985. The Buck Mark replaced both the Browning Challenger and International pistol models.
Over the years the design of the Buck Mark has remained very similar with refinements primarily in aesthetics, grips and available finishes. The Buck Mark pistol is designed with a straight blowback action, the frame is CNC machined from 7075-T6 aluminum. The gun comes equipped with a thumb safety as well as front and rear iron sights. Features for some models include a bull barrel, full length scope rail, wooden comfort grips, and Pachmayr grips. The magazine has a 10-round capacity. There are currently 15 models offered of the Browning Buck Mark pistol. The Browning pistol features a very smooth trigger action, not very common in many .22 caliber pistols today. The Buck Mark is reliable with just about any brand of .22 caliber ammunition currently available.
While a very popular and well regarded design, the Buck Mark pistol performs best when kept clean. Most .22 caliber ammunition is inherently dirty, and firing a pistol with a suppressor expedites the buildup of powder residue and grime. The disassembly and cleaning process is a bit more complicated and involved than most other .22 pistols.
One disadvantage to the currently available Buck Mark pistols is the lack of a factory-threaded barrel option. While threaded replacement barrels are available, it adds additional expense to the basic cost of the pistol.

Beretta Model 71

The Beretta Model 71 is a well built and finished single-action handgun that was produced from 1958 through 1985, with fine workmanship and quality control common on Beretta made firearms. The commercial Model 71 was once imported as the Jaguar. What makes the Beretta Model 71 particularly interesting is that they have served as the “special purpose” weapon of choice for the Israeli Mossad intelligence agency.
The Model 71 is a single-action semiautomatic with an 8-round magazine and fixed sights. The frame is aluminum and the slide is steel. On the left-hand side of the frame, there’s a slide-stop lever and a thumb-operated safety blocks the sear and hammer. On the right-hand side, there is a lever marked “disassembly” which, when moved forward, allows the removal of the slide and barrel assembly from the frame. The magazine release is a large, recessed push button on the lower left side of the grip. The left side of the slide reads: “PIETRO BERETTA, Gardone V.T. Cal. 22 L.R.” The right side: “P B–Made in Italy.” The importer isn’t saying what country the pistols came from, but an instruction manual written in Turkish has been found accompanying one pistol. The left side of the frame carries the original serial number and Italian proof marks which include an Italian production code for the year of manufacture. The production code on the test pistol consists of the letters “AH” inside a square box, indicating that it was produced in 1981.
The Model 71 uses Beretta’s characteristic open frame design with the exposed barrel. There are no plastic or zinc-alloy parts in the Beretta; the only parts not made of steel are the plastic grips, magazine follower and aluminum alloy frame. The Model 71 was the only pistol tested that worked flawlessly with every type of ammo tried, including the seemingly low-powered Aguila brand Super Extra Subsonic. Although the Model 71 tested had a factory threaded barrel, the 1/2-20 threads required an adapter to fit a 1/2-28 thread suppressor. The only problem in shooting the Model 71 is the sights are totally obscured by a suppressor. When a suppressor is on the barrel the pistol becomes a point-and-shoot weapon.

Advantage Arms

Advantage Arms makes .22 caliber conversion kits for Glocks, 1911 pistols, and Springfield Armory XD models. The company also offers threaded barrels for their kits.
Of course there are many more suitable host firearms for mounting a .22 caliber suppressor than those addressed here, however covering all of them is beyond the scope of this article. Nevertheless, having such a wide ranging choice of host weapons and suppressors is good for the shooting community.

By Al Paulson

Only accurate rifles are interesting. Ruger 10/22 and 77/22 rifles are very good values, and they can be customized into very accurate and user friendly rifles with a significant investment of time, effort and expense to make them truly interesting. That said, if you have participated in competition with a fine .22 rimfire target or biathlon rifle, then you must secretly lust after a better rifle to silence. Certainly hunting winter ptarmigan in Alaska at 80-110 yards with an Anschutz Model 54 that would deliver 1/4 MOA with Eley Tenex match ammunition ruined me for life. While the Ruger rifles are ideally suited for suppressing, in my heart of hearts, I’ve long wished that a suppressor manufacturer would introduce a line of suppressed rifles based upon a better rifle. A big part of the problem in my view is that a particular Ruger may or may not be accurate. Unconfirmed reports suggest that Ruger pays between $6 and $7 for a 77/22 barrel. To keep that price, barrels must be made quickly and tool life must be maximized. Therefore, bore and chamber dimensions can be expected to vary. So does accuracy. With careful ammunition selection, one 77/22 will group 3/8 inch at 50 yards, while another will group 3.5 inches- in my experience. Most seem to group around 1.5 inches. There are other compromises that must be made to keep the cost down, which also tend to give the Ruger less gravitas as a serious working tool compared to a fine European target or hunting rifle. I do not fault Ruger for making those choices. I have simply wished someone offered a suppressed rifle based upon a more serious shooting iron. Someone has. Mark White of Sound Technology now offers a suppressed Czech CZ 452-2E ZKM rifle that is worthy of the serious shooter. It is short, handy, robust, very quiet, and—above all—accurate.

Manufactured by Ceska Zbrojovka Uhersky Brod in the Czech Republic, the CZ 452 series of eight different models probably represents the best-selling .22 rimfire rifle design worldwide. Although relatively new to the United States, CZ 452s have been well known and highly regarded elsewhere for a long time. They are noteworthy for their quality, long service life, accuracy, and reasonable price. Their robust design of Mauser heritage features a receiver made from a steel billet, a hammer-forged barrel for accuracy and long life, adjustable trigger, cocking indicator, easy disassembly for routine cleaning and routine maintenance, and a very positive safety at the right rear of the bolt. While this is one of the best .22 rifle safeties I’ve ever seen, I should note that among us sourdoughs in Alaska, it was a solemn if unwritten rule that one never hunted with a round in the chamber. Safeties can fail or be dislodged by brush or a difficult climb up an escarpment. We only chambered a round if we were taking aim on a game animal or if we smelled a bear.

CZ receivers except the “American” models feature an 11 mm dovetail groove for scope attachment. The CZ 452 -2E ZKM model used by Sound Technology is based upon a variant that features the particularly handsome, classic design of a traditional European hunting rifle and the 11 mm dovetail. The CZ features an 18 lpi checkered, beech stock (stained walnut) with Schnabel fore end and beautifully designed and blued European sling attachments that cry out for a simple, soft, fine piece of leather as a carrying sling. The Lux model with stock of Turkish walnut is available for a few extra shekels. I think that would be a good investment, although I’m extremely happy with my beech model thus far. The barrel features an outstanding tangent sight that is adjustable for windage and elevation, with gradations out to 200 meters. It is an excellent sight for young eyes, although mature shooters will be better served by a scope. The tangent sight should really be removed to facilitate scope mounting, especially if the front sight will be removed anyway in the process of making a Silent CZ. In non-U.S. markets, CZ .22 rifles are available with the muzzles threaded to accept sound suppressors. U.S. rifle manufacturers take note. The CZ rifles come standard with 5-round magazines, and both 5- and 10-round spare magazines can be purchased. The barrels have somewhat tighter bores than U.S. standard, about 2 thousandths tighter. The CZ’s firing pin and extractors are far more powerful and robust than the Ruger’s, which are particular weaknesses in the American design. For example, Baikal Junior Steel ammunition may fail to fire in a Ruger, and it generally jams in a Ruger’s chamber and fails to extract. The CZ 452 always fires, extracts and ejects this tough ammunition without a hitch in my experience. All in all, White’s selection of the CZ 452-2E for suppressing was an excellent choice, since it is superior in a host of ways to the Ruger 77/22 and yet it costs about $110 less. How often can you get more for less?

If your primary interest is benchrest shooting, I’d probably opt for White to build his system on one of the American models in the CZ lineup. These feature 3/8 in (12.7 mm) dovetail groove for scope attachment and no iron sights to complicate scope mounting. The American models also feature a broader forestock that is better suited to shooting off sandbags. If you can’t decide which to get, buy one of each. The CZs are inexpensive enough to make that a realistic option. White also builds this design on the Ruger 10/22 for those who favor that rifle.

Table 1 compares the features of the standard CZ 452-2E and Sound Technology’s Silenced CZ rifles. The silenced CZ features White’s latest iteration of his enormously popular M-Can, which is noteworthy for its superb sound reduction, unusual self-cleaning properties, ease of routine maintenance when required, robust construction, extraordinary service life, and—above all—accuracy. This M-Can is 7.38 inches long and 1.25 inches in diameter. The Silenced CZ weighs 6.3 pounds, which is 0.2 pound lighter that the unmodified rifle with beech stock before the conversion. Built like an M1A1 main battle tank, the M-Can is welded to the barrel, so misalignment will never be an issue. This is a one-stamp gun despite the fact that I opted for a 12.4 inch barrel.

It is important to note that even 12.4 inches is longer than White’s preferred embodiment, for a variety of compelling reasons. My logic for the 12.4 inch barrel was both cosmetic and practical. From an aesthetic point of view, a shorter barrel would have required whacking off the front of the forestock, and I didn’t want to lose the graceful Schnabel fore end. Furthermore, a 12.4 inch barrel comes extremely close to providing maximum bullet velocity, enabling me to tailor velocity and terminal ballistics by the selection of ammunition.

White prefers a shorter barrel to ensure that standard velocity target ammunition will stay subsonic under a wide range of environmental conditions. Note that CCI standard velocity and Aguila SE Subsonic have lower velocities than Remington, and so are more suppressor-friendly in this regard. The Aguila solid point subsonic, for example, is very good ammunition and produced an average muzzle velocity of 1,011 fps out of the Suppressed CZ at 95 degrees F (contact Centurion Ordnance, Dept. SAR, 11614 Rainbow Ridge, Helotes, TX 78023; phone 800-545-1542).

A shorter barrel may also be more accurate than a standard barrel, since it may be stiffer and less subject to barrel harmonics. Extensive research into the effect of barrel length versus velocity using a wide variety of ammunition (see Silencer History and Performance, Volume 1, pages 226-235) has clearly demonstrated that the velocity of standard velocity ammunition is at or near maximum with a 12 to 14 inch barrel. By then, no more energy can be transferred from the modest 1 to 1.4 grains of powder combustion gases to the projectile. Friction between the bullet and the bore becomes an increasingly significant factor with longer barrels.

Trigger pull was a consistent if heavy 4.0 pounds, and it exhibited more creep and overtravel than I liked. After several hundred rounds, the creep mellowed out, but trigger pull weight and overtravel remained issues. Sound Tech recently started installing trigger overtravel screws for a modest fee. This modification makes a big difference. Dr. “Nick” Panisuan of Bangkok, Thailand, has developed the definitive methodology for doing trigger jobs on the CZ 452 and an American has documented the procedure, with illustrations, on the Internet. Go to http://projects/chatrifleclub.org/cz452mods.html. Furthermore, at the CZ Forum archives at www.rimfirecentral.com explains how to turn the CZ trigger in to a crisp 8 to 10 ounce trigger pull comparable to a $1000 Anschutz. The CZ Forum also provides a variety of other techniques to improve the CZ’s trigger, as well as a source for replacement springs to facilitate a great trigger job. Bear in mind, however, that this is a particularly nasty trigger to reassemble, so I’d personally hire the work out if you can find a qualified gunsmith. Mark White at Sound Technology will do an excellent trigger job, eliminating overtravel and bringing trigger pull down to 2 pounds, for $55. That’s a mandatory investment in my book.

I evaluated Sound Technology’s Silenced CZ using four kinds of ammunition: Remington high velocity (R HV), CCI Green Tag standard velocity target (CCI SVT) since a superior rifle merits a better target round than Remington’s standard issue, Remington subsonic (R SS), and Russian Baikal Junior Brass subsonic (BJB SS). I used a Ruger 77/22 with 12 inch barrel as the reference standard for unsuppressed performance and a Tasco World Class 6-24x44mm AO scope for accuracy testing, although I eventually replaced it with a much handier Simmons Model 1031 22 MAG 4×28 scope. I was not happy with how the Simmons rings fit the 11 mm dovetail, so I immediately replaced them with Bushnell 76-3022 rings that seem to grip the 11 mm dovetail without a problem, provide just enough clearance for the bolt handle for handy manipulation without being too high for a proper cheek weld, and are much cleaner visually than Simmons or Weaver mounts. CZ offers excellent if expensive steel mounts. Many end-users seem to be particularly happy with mid-priced BLK scope mounts (the same mount works both for 11 mm and 3/8 inch dovetails). BLK mounts can be purchased from Silver Streak Sports; check out their website at silverstreaksports.com/BLK.htm.

I should note that the use of Baikal Junior Steel subsonic (a slightly cheaper alternative to Junior Brass) will quickly kill soft and feeble Ruger firing pins and extractors, but the CZ seems to have no problem with that ammo. I also find it interesting that Eley uses Baikal ammunition for their quality control program when manufacturing Eley premium match ammunition. The fact that the Silenced CZ likes Baikal Junior Steel is particularly gratifying since I’ve got 30,000 rounds of the stuff languishing in storage. The mean (average) sound pressure levels, net sound reductions, and three-round groups (measured center to center) appear in Table 2. The temperature during the testing was 85 degrees Fahrenheit, and the speed of sound was 1,144 fps.

Sound signatures of 112 decibels with standard velocity and subsonic match are nothing short of wonderful. The sound of the striker falling on a CZ 452 is 110 decibels, so Sound Technology’s Silenced CZ is only 2 decibels louder than action noise with the rifle’s most accurate round tested thus far, CCI Green Tag. Note that the muzzle velocities of standard velocity and subsonic rounds are almost identical; clearly a 12 to 12.4 inch barrel is an extremely efficient length. Three 3-round groups averaged 0.18 inch at 50 yards. I haven’t fired such small groups from a .22 rifle in a long time. Wow!

When I grab a silenced bolt-action rimfire rifle these days, it is Sound Technology’s Silenced CZ. It is handsome, affordable, robust, low maintenance, handles and balances to perfection, delivers superb sound reduction (within 2 dB of firing pin noise), and qualifies on the single most important criterion for a silenced rifle in my opinion. It is extraordinarily accurate-nearly three times more accurate than the unmodified CZ 452 rifle when using CCI Green Tag match ammunition. White’s reputation as an accuracy guru is supported by the performance of the Silenced CZ. Furthermore, the Silenced CZ fits my body and my biases to perfection. Only accurate rifles are interesting. The Silenced CZ from Sound Technology is the most interesting suppressed turn-bolt .22 rimfire rifle I’ve yet encountered, and I can recommend it with unbridled enthusiasm.

For more information on the Silenced CZ, contact Sound Technology, Dept. SAR, P.O. Box 391, Pelham, AL 35124 (phone and fax 205-664-5860; URL http://www.soundtechsilencers.com). For information on CZ rifles in general, contact CZ USA, Dept. SAR, 1401 Fairfax TFWY, B-119, Kansas City, KS 66115 (phone 1-800-955-4486; e-mail czusa@gvi.net; website www.cz-usa.com).

1997 Silencer Trials

Dateline: Knob Creek, KY, May 22, 1997. This day was an unprecedented event in the annals of small-arms history; almost all of the silencer manufacturers in the United States came together to have the performance of their sound suppressors tested side by side, using scientifically appropriate sound test equipment. This was very much a team effort with me supervising the tests, Dr. Phil Dater handling the Larson Davis Model 800-B sound meter with Larson Davis 2530-1133 1/4 inch random incidence microphone and automated data recording using a Hewlett-Packard OB-425 computer and software he developed for the purpose, and Dan Shea organizing the scheduling, volunteer shooters and the ammunition supply. We also used a Pact MK-IV Timer/Chronograph with MK-V skyscreens for recording projectile velocities.

I figured we had time to run 60 tests that day, but the demand for data was so intense that we somehow managed to squeeze in 163 test strings. We gathered as much data in a day as I normally produce in a year, giving all of the participants a chance to see how their products measured up to the competition in terms of hard numbers and subjective qualities such as tonality.

It’s hard to adequately express, much less overstate, my admiration for all of the participants since the complete spectrum of the industry was represented. Relatively new, one-man operations competed against well-established design teams of more well-known companies like Knight’s Armament and Gemtech, all competing on a level playing field. Some participants were pleasantly surprised by the performance of their products, while some discovered that individual products needed some refinement.

Several manufacturers expressed displeasure that a particular model did provide nearly as much sound reduction, looking at an average of ten shots, as a similar model of a competitor. Yet that louder model might be an integrally suppressed .22 pistol that delivers more velocity, which is important for anyone shooting a live target instead of punching paper or pop cans. Another suppressor might be louder than a competing model, but it’s half the price of the ultraquiet competitor, or significantly shorter or lighter or more durable. The sound moderator from one manufacturer comes to mind as an example; it is small, light and durable while providing significantly less sound reduction than the manufacturer’s own and competing full-sized suppressors. But the compact size is especially valuable when fitted to an entry weapon, and the moderator will enhance command and control while protecting the operator from short-term and long-term hearing loss. A silencer or moderator that is relatively loud may still be an appropriate tool for a given set of circumstances.

There are more subjective considerations as well. For example, a somewhat louder suppressor or integrally suppressed firearm with superb craftsmanship and cosmetics might make a more handsome and appropriate family heirloom. Sometimes maximum sound suppression is, indeed, the single most important design or performance criterion when selecting a suppressor for a particular application, but sometimes it’s well down on the list of priorities. Here’s a list of design and performance criteria that should be used when evaluating suppressors. How these criteria are ranked in terms of priority will vary with each and every end-user’s circumstances and requirements.

Criteria for Suppressor Selection

1. length
2. diameter
3. weight
4. materials
5. durability of construction (operational lifespan)
6. tonality of sound signature (dominant frequency or pitch)
7. sound pressure level of sound signature (or net sound reduction)
8. first-round pop
9. wet or dry technology?
10. effect on projectile velocity
11. effect on accuracy
12. handiness (human engineering)
13. cost
14. appearance
15. maintenance requirements
16. mounting system
17. type of finish
18. reputation of manufacturer
19. time to drain if full of water (relevant for some SpecOps requirements)
20. time to mount and dismount from weapon (relevant for some SpecOps requirements)
21. quality control
22. ability to deliver required quantities within any time constraints

The learning process at the suppressor trials was by no means limited to the sound testing and discussions on design and performance criteria. Throughout the very long day, the various manufacturers chatted with each other, discussing the fine points of suppressor design, such as how a designer was trying to manipulate gas flow with a new baffle design, problems trying to reduce first-round pop, or the use of exotic materials and fabrication techniques. Suppressor designers frequently offered suggestions to a competitor on how to solve a particular problem. That is not to say that folks swapped their most valuable proprietary knowledge, but they shared information of a depth and quality that I found both remarkable and heartwarming. I know of no other small, highly competitive industry where the principals are so gracious and genuinely helpful to their competitors. Mark White of Sound Technology added to this sense of community by throwing a barbecue for all of the participants at the end of the day.

While space constraints preclude reporting the data here, it is appropriate to highlight a sampling of products that impressed me. Ralph Seifert of R.A.S.E., for example, has developed an innovative baffle design for the .22 rimfire that provided impressive performance in his Labyrinth (an integrally suppressed Ruger 10/22 rifle) and Photon (an integrally suppressed Mountain Eagle pistol). The Photon is remarkably light since it uses a largely plastic pistol plus an innovative carbon fiber suppressor tube. The Photon also features a reinforced barrel which may well eliminate the durability problems often associated with earlier attempts to suppress this pistol by other manufacturers.

Don Austin Wagenknecht brought a particularly diverse product line, ranging from a suppressed cane gun, to an efficient suppressor for the Cobray M11/9 submachine gun, to an ingenious muzzle can for the S&W Model 422 pistol.

While John’s Guns suppressed Marlin Camp Carbines provided good performance in a handy package, the integrally suppressed Ruger 22/45 pistol and Ruger 10/22 rifle designed by John Tibbetts were particular crowd pleasers. His suppressed Ruger Mark II was the quietest integrally suppressed Ruger pistol of the day, beating such industry benchmarks as the outstanding Operator from Gemtech and revolutionary Amphibian from AWC Systems Technology. His Ruger 10/22 was also one of the quietest of the intergrally suppressed 10/22s evaluated during the trials.

Mark White introduced one of the most popular designs of the day—as evidenced by the crowd of dealers wanting to test fire the system during the picnic following the trials—with his Dark Star suppressor mounted on a Ruger Model 96 lever-action rifle firing 260 and 325 grain subsonic .44 Special loads. Originally developed for 7.62x51mm sniper rifles, this superb suppressor made the .44 rifle quieter than a factory original H&K MP5 SD while delivering far superior terminal ballistics. The crowd waiting to fire the suppressed .44 only dispersed when White finally ran out of ammunition.

Jonathan Arthur Ciener, who is the oklest continuously operating suppressor manufacturer in the United States (and one of the oldest in the entire world), had such a confidence in his earliest work that he brought original prototypes from the 1970’s for testing. Even though these designs are several decadesold , I was most impressed by their durability, outstanding workmanship, and the fact that they still provided solid sound reduction compared to the very latest generations of suppressors brought by other. Perhaps the best way to put Ciener’s work in perspective is to note that he was the first to design an effective suppressor for the UZI submachine gun. The salient point is that Ciener developed that UZI suppressor soon after a team of scientist working for Uncle Sam had concluded that it was theoretically impossible to design an effective and practical suppressor for the Uzi, after the goverment had thrown cubic dollars and numerous engineers at the project. It is safe to say that Jonathan Arthur Ciener has played a piotal role in the development of silencer technology as well as in the popularization of that technology with American civilians. The entire industry owes him a considerable debt of gratitude for his contributions.

SIOPTS provided a titanium suppressor with quick-mount system that fastens directly to an unmodified M16A2 or M4 flash hider, something that no one else has accomplished to my knowledge. Furthermore, SIOPTS developed a very heavy, frangible tungsten subsonic round that actually cycles the action—another “impossible dream” that has become reality. While the round provided disappointing accuracy during the trials, it turned out that a loose flash hider on the rifle was the culprit. Subsequent testing demonstrated that the round is capable of delivering a head shot at 100 yards, as long as a barrel with a 1 in 7 rate of twist is used.

Joe Gaddini of SWR was the only manufacturer to bring suppressors for the .40 S&W variant of the MP5 submachine gun, offering a compact sound moderator, a medium-sized suppressor, and a full-sized suppressor. A former engineer at Knight’s Armament Company, Gaddini takes great pains not to infringe upon the proprietary designs of KAC, which is something I greatly admire. His design strategy is to minimize first-round pop at the expense of the average sound pressure level, based on the premise that—for serious applications—the sound signature of the first shot is most critical. While his .45 caliber suppressor for the H&K Mark 23 pistol is louder than the KAC SOCOM suppressor, for example, the amount of first-round pop is less.

That said, the performance of the SOCOM suppressor designed by Doug Olson and Reed Knight was most impressive, producing a sound signature that was less than many suppressed .22 rimfire rifles and pistols. As impressive as the sound signature was, I was even more impressed by the suppressor’s overall design in terms of baffle configuration, fabrication, metallurgy, durability, and finish. Just the tooling to manufacture the complex fluted baffles cost several hundred thousand dollars, and a robot performed all of the complex welding to provide excellent quality control. The Nielsen device in the rear of the suppressor that enables the pistol to cycle reliably—together with the ability to easily zero the point of impact when mounting the suppressor on any pistol—represent remarkably sophisticated engineering. While the Mark 23 pistol with Knight suppressor is a large and heavy package on paper, the reality of handling this system is quite different than mere statistics suggest. Balance and handling are superb, making it easy to deliver rapid double taps at 50 yards. The pistol’s sound signature is significantly quieter than an MP5 SD integrally silenced submachine gun, and it delivers vastly superior terminal ballistics. The H&K Mark 23 pistol and Knight suppressor together form a new and impressive state of the art.

Gemtech fielded a new 9mm pistol suppressor called the Vortex-9, which provided a remarkable 28 dB reduction when fired dry on a Beretta 92F pistol and 35 dB after a half teaspoon of water was poured into the back of the suppressor and allowed to seep through ported baffles into structures that trap the water so it doesn’t leak from a holstered suppressor. The Vortex-9 did not smoke or spatter the operator with droplets of greasy grime, and the impressive performance when wet seems to last for two magazines-worth of shooting. While Gemtech’s M4-96D quick-mount suppressor for the M4 carbine normally equals or slightly outperforms the KAC M4-QD with M855 ball ammo, the Knight suppressor dramatically outperformed the Gemtech suppressor with Winchester USA (so-called White Box) 55 grain fodder. While most suppressors perform very well with Winchester USA pistol ammunition, we learned during the course of the trials that many suppressors do not perform as well as expected when employed with Winchester USA ammo of rifle caliber. Winchester has just discontinued the production of rifle caliber paramilitary ammunition, so this phenomenon can be relegated to a point of historic interest.

John Weaver of JRW fielded a diverse array of suppressors, from an impressive integrally suppressed Ruger 10/22 rifle to a suppressed Sako rifle in .300 Whisper that was quieter than an H&K MP5 SD. JRW’s OTB 22 muzzle can provided excellent performance shot dry on a Marlin 39A rifle and wet on a Walther PP pistol.

The integrally suppressed firearms made by Curtis Higgins of S&H Arms of Oklahoma provide an almost ideal maximum projectile velocity without sacrificing sound reduction. In fact, the

S&H suppressed 10/22 rifle was significantly quieter than most silenced 10/22s I’ve tested. The impressive R.A.S.E. 10/22 beat the performance of the S&H gun by 1 decibel but delivered 43 fps less velocity. I’ve tested some 10/22s that delivered nearly 200 fps less velocity without being nearly as quiet as the S&H gun. It is interesting, however, that one of my favorite .22 pistols of the day was also one of the loudest of its type. Higgins developed an exquisitely handsome suppressed High Standard pistol that is 12 decibels louder than his standard suppressed Ruger Mark II pistol, and the silenced High Standard also has a substantial first-round pop. But it uses a suppressor tube that has a diameter of just 7/8 inch, which enables Higgins to make a package of extraordinary aesthetic appeal. Finally, I can’t go on without mentioning the S&H clone of the H&K MP5 SD, which delivered substantially better sound reduction and substantially higher projectile velocity with both supersonic and subsonic ammunition than a factory original MP5 SD. That’s a most impressive engineering achievement.

Dale Summers of Summers Machine Enterprises produces integrally suppressed Ruger rifles and pistols that give a good mix of sound reduction and projectile velocity, while delivering much better than average accuracy. Summers has a small but fiercely loyal following of regular customers, one of whom provided the pistol for testing. The Spec Op’s Shop provided an interesting array of titanium suppressors for the Ruger 22/45 pistol, Beretta 92F pistol, MP5 submachine gun, Remington PSS rifle, and Colt M4 carbine. The Spec Op’s Shop 9 inch variant of the 5.56mm Viper outperformed the very successful HRT from AWC Systems Technology.

Finally, we tested the subsonic 5.56x45mm White Tip ammunition developed by Whit Engel of Engel Ballistic Research. Using an aftermarket M4 clone and a Gemtech M4-96D suppressor, we tested two variants of subsonic ammunition: one features a 55 grain projectile, while the other uses a 69 grain projectile. The suppressed sound signatures were 117 and 118 decibels, respectively, which is quieter than many suppressed .22 rimfire rifles and pistols. Using a barrel with a twist of 1 in 9, these subsonic rounds provide the capability to deliver head shots at 80 yards.

My thanks to all of the suppressor manufacturers and volunteers who made the 1997 Silencer Trials a success. Forthcoming issues of Small Arms Review will provide a more detailed examination of sound suppressor technology from each of the participants in the 1997 Silencer Trials. We hope to make this an annual event which will draw participants from throughout the United States and overseas as well. The trials provided a great learning experience for all of the manufacturers, volunteers, and dealers who participated in the event.

Participating Manufacturers

Don Austin Wagenknecht
12400 Blue Ridge Blvd.
Grandview, MO 64030

Engel Ballistic Research
Rt. 2, Box 177C
Smithville, TX 78957

Gemtech
P.O. Box 3538
Boise, ID 83703

John’s Guns
3010A Hwy. 155 N.
Palestine, TX 75801

Jonathan Arthur Ciener, Inc.
8700 Commerce Street
Cape Canaveral, FL 32920

JRW
3425 Yule Tree
Edgewater, FL 32141

Knight’s Armament Co.
7750 9th Street SW
Vero Beach, FL 32968

R.A.S.E.
P.O. Box 866
Cocoa, FL 32926

S&H Arms of Oklahoma
P.O. Box 121
Owasso, OK 74055

SIOPTS
570 A Industrial Park Dr.
Newport News, VA 23608

Sound Technology
P.O. Box 391
Pelham, AL 35124

Special Op’s Shop
P.O. Box 978
Madisonville, TN 37354

Summers Machine Enterprises
Route 7, Box 672
Thomasville, NC 27360

SWR
119 Davis Rd., Suite G-1
Martinez, GA 30907