by Frank Iannamico
A Brief History of Sound Suppressors
Many of us grew up watching television and movie actors posing as secret agents, mercenaries, and gangsters handily dispatching their adversaries with one quiet shot from a “silencer” equipped pistol, submachine gun and yes, occasionally, a revolver. One thing all of their weapons had in common was that there was virtually no sound except for a whispered “pfft.” That is the way suppressed firearms were generally depicted in Hollywood where drama trumps reality. However, some of the more recent Hollywood offerings have actually become more detail oriented; having “silenced” weapons that emit realistic sounds, and even firefights where the hero performs occasional magazine changes.
The word “silencer” has become engrained in American lexicon by the movies. A more accurate term would be sound “suppressor,” but if you explained to the average non-firearms individual that you had a “suppressor” on your pistol, chances are good that they would have no idea what you were talking about.
The origin of the suppressor, aka the silencer, dates back to the early 1900s. Although there were many patents filed for suppressors, most were only conceptual in nature and there were few actual functioning units. The first recognized commercial sound suppressors were the Maxim Model 1909 and Model 1910, invented by Hiram Percy Maxim, son of Hiram Stevens Maxim famous inventor of the Maxim machine gun. The original intent of the sound suppressor was to engage in sport shooting without the associated muzzle blast. This was desirable before the widespread use of hearing protection. Shooting “quiet” firearms was also intended to be appealing to women. As depicted in Maxim’s advertising, there was no thought of evil intent. Sales of Maxim’s “silencers” were unrestricted and could be purchased right over the counter at the local hardware store, or by mail order. The Maxim silencer was also advertised as a muffler for small gasoline engines.
Early “silencers” were not thought to pose any threat to the average citizen until a few criminals discovered that they could dispatch their enemies without calling attention to themselves. Before long, the innocence, and original intent of the “silencer” was lost and now the general public believed that their only purpose was criminal and only criminals had them. Hollywood stepped in and perpetuated the illegal use of “silencers” in the movies, and often suggested that constructing a silencer was as easy as empting a can of beer and filling it with steel-wool. Hollywood also substituted pillows, and even potatoes, as expedient devices to suppress muzzle blast. Criminal use of sound suppressors, both real and imagined, lead to their inclusion in the National Firearms Act of 1934 restricting their possession, along with machine guns and short barrel weapons. Along with legitimate civilian use, development of sound suppression devices for firearms virtually ended.
During World War II, the development and use of suppressed weapons resumed and were fielded by both the allies and the enemy. Some of the better known allied weapons were the High-Standard suppressed HD Military used by the OSS, the Welrod suppressed pistol and DeLisle suppressed Carbine both used by the British as well as the suppressed U.S. .45 caliber M3 grease gun and British 9mm Sten Mk IIS. After the war, interest in the research and development of suppressed weapons in the U.S. ceased once again.
During the post-World War II era, an ex OSS officer by the name of Mitch WerBell III decided to get into the clandestine weapons business. His specialty was sound suppressors and he started a company named Sionics that specialized in counterinsurgency equipment. The acronym Sionics stood for “Studies in Operational Negation of Insurgency and Counter Subversion.”
Sionics was a company that supplied suppressors and similar items for covert operations by military and CIA type organizations. The suppressors that Sionics designed and sold used a series of metal shoestring eyelets, spiral baffles and wipes to suppress muzzle blast. The life expectancy was approximately 200 rounds before the unit’s efficiency deteriorated and the wipes needed replacement. A wipe replacement kit was available as a separate item. Mitchell WerBell’s achievements in suppressor design were often regarded as the most significant advancements since Hiram Maxim’s silencers were introduced at the turn of the century. WerBell was granted three patents covering his suppressor designs. The primary customer of Sionics was the U.S. Government. The product line consisted of an array of suppressors for U.S. sniper rifles, primarily the M14 and M16, as well as suppressors for pistols and submachine guns.
During 1969, Mitch WerBell was planning a trip to South Vietnam to demonstrate his company’s suppressors for the U.S. M14 and M16 rifles. Prior to this trip, WerBell and Gordon Ingram were unknown to each other. However, mutual friend Thomas B. Nelson knew both men and their respective talents. Mr. Nelson suggested that WerBell arrange a meeting with Ingram. When the two men met in Los Angeles, WerBell was immediately impressed with Ingram’s Model 10 as the perfect covert weapon to attach a Sionics suppressor. WerBell struck a tentative deal with Ingram, whereby he would take possession of Ingram’s Model 10 submachine guns to demonstrate them along with his Sionics suppressors. The little Ingram submachine was an immediate hit in Vietnam and everyone wanted one. WerBell immediately contacted the Sionics Company officials back in Georgia, instructing them to contact Gordon Ingram and begin negotiations for the rights to manufacture his submachine gun. Shortly after Ingram joined WerBell’s company, the name was changed to The Military Armament Corporation or MAC for short. The Sionics suppressor designs were manufactured by MAC until the company went out of business. A short time later RPB Industries and SWD continued to manufacture WerBell’s basic suppressor designs. These were the first suppressors that were readily available to the civilian market. Unfortunately, due to some dubious business practices, many of the sales were made without the suppressors being registered. This was made possible by the customer purchasing the internals components from one company and the outer tube assembly from another (usually related) firm. The proliferation of suppressors obtained through this marketing method are the primary reason that it is now illegal for anyone but a Class II manufacturer to possess any suppressor components or spare parts.
Since those early days of civilian suppressor ownership, technology for sound suppression has vastly improved and current interest in suppressors has reached levels that Mr. Maxim and WerBell never could have imagined. The growing interest has spawned a large number of new suppressor companies and with it great strides in suppressing muzzle blast in modern, wipeless units that are far smaller and lighter than the original Sionics designs. Gone are the days of the automobile muffler-size suppressors with wipes that lasted only several hundred rounds before needing to be replaced.
One of the most popular suppressors today are those made for .22 caliber rimfire weapons. The ammunition is very inexpensive and standard velocity .22 ammunition will usually not exceed the speed of sound in pistols. Until recently, many manufacturers concentrated on producing sealed, non-serviceable units. The reason was two-fold, for one it is not legal to possess any individual suppressor components and, second, an improperly assembled suppressor could result in damage to the unit and/or the shooter. However, due to growing customer demand, many manufacturers have introduced user-serviceable suppressors. Most of the suppressor’s internals have been designed to be taken apart and reassembled with little chance of being put back together incorrectly. Due to .22 caliber rimfire ammunition being inherently dirty, user-serviceable units have become quite popular.
The Garrote Suppressor
One of the more recent rimfire suppressors to appear on the market is the Garrote, offered by Subgun Ordnance, the same company that markets the popular .22 caliber conversion kit for the full-size Uzi submachine gun. (SAR Vol. 13, No. 2.) The Garrote is a small, lightweight, and economically priced sound suppressor that can be easily disassembled without tools, making it fully user-serviceable. The Garrote is a modern, wipeless design, which is made entirely from aluminum, except for its 1/2-28 titanium threaded insert, designed to keep it from galling onto the barrel of the host weapon. The Garrote is also full-auto rated, making it the perfect accessory for Subgun Ordnance’s .22 Uzi conversion. The suppressor tube is 5.6 inches long with an outside diameter of one inch, and a weight of only 3.7 ounces. The internal components consist of a blast baffle followed by six baffles with integrated spacers. The end cap is threaded to facilitate removal and can be removed or tightened with a coin. The tube is anodized in an attractive flat black color.
The Garrote is designed to be mounted on 1/2-28 (Class 2A) threads, with a maximum barrel thread length of .4 inch. The threads must be absolutely concentric with the bore of the barrel, and have a 90-degree rear shoulder perpendicular to the bore. What this means is, have your barrel professionally threaded by a machinist or gunsmith who is familiar with threading barrels for mounting suppressors.
For the best results in sound suppression, Subgun Ordnance recommends standard velocity rimfire ammunition, such as CCI Standard Velocity, CCI Green Tag or Remington Subsonic. High Velocity .22 rimfire such as the CCI Stinger and Remington Yellow Jacket will reach supersonic velocities, resulting in a somewhat loud “crack” when the bullet exceeds the speed of sound. Use of .22 Magnum .17 HMR, Aguilla SSS 60-grain Subsonic, and all types of center fire ammunition should not be used with the Garrote suppressor, and their use will void the manufacturer’s warranty. Due to the significant powder residue, condensation, and vaporized lead, generated by rimfire ammunition, the manufacturer recommends cleaning the Garrote after each use, or at intervals not to exceed 250 rounds. Failure to do so may result in a suppressor that will be difficult or impossible to disassemble outside the factory.
For routine cleaning, WD-40 is recommended; for extremely dirty units, 0000-steel wool, Scotch-Brite pads or a stiff toothbrush can be used. Glass-bead blasting to remove carbon is not recommended and will void the warranty. Many popular gun cleaning solvents such as Hoppes, Sweets and GI bore cleaner will damage aluminum, and should not be used for cleaning any of the aluminum components. Water and all water based cleaning agents like SLIP-2000, MP-7 and Simple Green should also be avoided.
The Garrote manufacturer’s literature claims a sound reduction of 38 dB. While no sophisticated test equipment was available during our evaluation; the suppressor was tested dry, on a Walther P22 semiautomatic pistol and an Uzi submachine gun. The sound emitted was comparable or slightly quieter when compared to similar units. In addition to muzzle blast, there are several other factors that need to be considered; the noise generated by the weapon’s action, noise emitted from the ejection port and the sound of the projectile striking the target.
For an in depth scientific comparison of popular suppressor of all calibers, visit the Silencer Research website at; www.silencerresearch.com/
Phone: (262) 770-9894
Fax: (262) 635-8305
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