During 2003 Gemtech announced the availability of the upgraded Outback II that had a threaded insert made of titanium, replacing the aluminum insert used in the first design.

By Frank Iannamico

For many years suppressor manufacturers have been offering their customers products that could not be disassembled for servicing. The primarily reason was a concern of the customer possibly incorrectly reassembling the internal components resulting in damage to the unit, or personal injury. During the 1970s the Military Armament Corporation experienced such a problem with their suppressors, and soon began to use a thread locking compound on their endcaps to discourage disassembly. Like many modern companies MAC suggested to their customers that they return their suppressors to the factory for servicing. This protocol is fine as long as the manufacturer is still in business, which in many instances might not be the case, like MAC have been out of business for many years. Generally speaking most companies will not service suppressors made by someone else.

The sound suppressors that require the most attention are those designed for .22 rimfire cartridges, an inherently dirty round. With a lot of use, a .22 caliber suppressor will gradually lose its efficiently, and at the same time get heavier with an accumulation of lead and powder residue. Cleaning suggested by many manufacturers is to immerse their sealed suppressors in a particular chemical solution, which does little or nothing to remove carbon fouling and lead. Previously, the thorough servicing of sealed suppressors had to be performed by the manufacturer, if they offered such a service. Factory servicing usually consisted of removing the old baffles and replacing them with new ones. When extreme fouling was present, and the old baffles could not be removed by normal methods, they often had to be machined out of the tube on a lathe. Baffle replacement is not possible by individual owners, because possession of individual suppressor parts is a felony. Federal laws do not allow the factory replacement of the serial numbered tube, unless the original is defective. Replacing the suppressor tube with a new one would require a second $200.00 transfer tax to be paid.

Returning a suppressor to the manufacturer for routine servicing can be inconvenient and time consuming for the customer. If the suppressor manufacturer is no longer in business, a heavily fouled, and increasingly loud suppressor, becomes nothing more than an expensive paperweight. The aforementioned reasons are why customers began to request that manufacturers offer suppressors they could service / clean themselves. As a result, companies have now begun to offer units that could be easily disassembled. The new serviceable suppressors usually come with special tools to remove the endcaps. Some manufacturers offered optional tools to push baffle stacks out of the tubes to minimize the possibility of damaging them. New baffle stack and monocore designs made it less likely that the customer could assemble their suppressors incorrectly.

Owners of older, factory sealed suppressors began to seek ways to upgrade their cans to a user serviceable configuration. Seeing a business opportunity, enterprising Class II manufacturers began to offer a service to open up sealed suppressors, and clean or replace their internal components. This service added a new term “jail break” to the NFA community lexicon, referring to the opening up a formerly sealed suppressor tube, making it user serviceable. Some suppressor manufacturers offer the service on their products, and there are a few independent companies that will perform the work on most suppressors, regardless of the manufacturer.

Now that user serviceable suppressors are common, there are a few caveats. If not disassembled and cleaned on a regular basis, the endcaps may be difficult to loosen and the baffles inside the tube can become extremely hard to remove. Attempting to disassemble a heavily fouled “user serviceable” suppressor can often result in damaged baffles or worse, a permanently damaged tube. There also exists a potential health hazard after exposure to lead and other contaminants present in a suppressor. However, as long as the suppressor owner remains aware of the negative aspects, they should not encounter any problems.

Suppressor Cleaning

After disassembly, there are a number of different methods for cleaning baffles and tubes. The options include chemicals, ultrasonic cleaning or media blasting. The method used on any particular unit depends on what materials were used in its construction. When possible always follow the manufacturer’s recommendations. Using the wrong method when cleaning suppressor components can lead to permanent damage. When using chemicals, be aware there can be potential health and environmental concerns when disposing of contaminated liquids.

The Gemtech Outback Suppressor

Gemtech’s Outback .22 caliber suppressors, first introduced in 1999, have been very popular among suppressor aficionados. The first Outback models had aluminum baffles inside a non-customer serviceable factory sealed aluminum tube. One concern customers expressed with the original Outback model were the ½-28 threads used to attach the suppressor to a barrel were also aluminum. Some were afraid that the aluminum threads could be easily stripped by over tightening or cross threading. According to the company, of the thousands of Outback suppressors sold, only two were returned to repair their threads. In both cases the threads were still safe and met ANSI standards. However, Gemtech listened to their customers and changed the thread insert to titanium on the new Outback II in 2003. Titanium was chosen over stainless steel because stainless threads have the propensity to gall if the weapon’s barrel threads are a few thousands oversize. Galling can make the suppressor very difficult to remove, increasing the chance of damage to both the barrel and suppressor.

The manual that came with the original Outback stated that the factory “discourages any attempt at disassembly of the unit. Internal parts orientation is critical to the efficient operation of the suppressor, and reassembly requires special tooling and jigs available only at the factory. Any attempt at disassembly will void the warranty”.

During 2011, Gemtech began to manufacture the user-serviceable .22 caliber Outback II D with a removable front cap. The rear endcap was secured with Loctite, as removal and replacement could affect alignment and runout. During manufacture, the titanium thread insert is internally threaded after the rear mount has been secured in place with Loctite to guarantee true running. The baffle stack can be pushed out from the rear with a 3/8” wood dowel.

At the same time, the company began to offer a customer program to update older Outback and Outback II suppressors with the latest baffle design and removable endcaps.

For their 20th anniversary in 2013, Gemtech offered their Limited Edition Outback II T model made of lightweight titanium. The tube of the Limited Edition Outback is a silver satin color.

During 2014 Gemtech introduced a new .22 rimfire suppressor, the GM 22. In place of conventional baffles, the new GM 22 features Gemtech’s patented G-Core, a one-piece CNC machined 7075 aluminum monocore design. In addition to .22LR, the GM 22 is rated for full-auto fire (.22LR only) and for .22WMR and .17HMR cartridges. The overall length of the GM 22 is 5-inches, with an outside diameter of 1-inch, and a weight of 2.5 ounces. The finish is high temperature MIL-A-8625 hard anodize. The one-piece G-Core design makes disassembly easy with common tools, and simplifies cleaning.

For customers who own older Gemtech Outback, Outback II, Outback II D or Alpine suppressors, the company offers the Improved Outback Upgrade program. The service includes opening up the original tube, removing the old baffles, and installing a new one-piece G-Core. After the upgrade the G-Core Outback is rated for .22WMR and .17 HMR calibers. The G-Core makes disassembly of the Outback for maintenance easy. The upgraded suppressor is returned to the customer in a new box with a manual, Molle pouch and G-Core patch. The G-Core upgrade can also be performed on number of competitor’s .22 caliber suppressors.

Gemtech also manufactures a Quick Detach Adapter system that allows the installation or removal of any .22 caliber suppressor in seconds. The adapter, made of high strength aluminum and stainless steel, is a smaller version of Gemtech’s popular 3-lug Quick Mount system used on their 5.56 and 7.62 suppressor applications.

To enhance suppressor performance, Gemtech offers their own brand of .22LR caliber ammunition manufactured to their specifications. The Gemtech ammunition features a special 42-grain round nose bullet with a premium lubricant and a cleaner burning powder. The subsonic velocity is 1050 feet per second. The brass case is engraved with the Gemtech logo headstamp.

By The Small Arms Review Editorial Staff

Company: GEMTECH
Model: The ONE
Caliber: 7.62 NATO / 308
Length: 7.5”
Diameter: 1.625 with Shroud
Weight: 16.3oz
Factory Tested Sound Reduction: 32dB
Materials: Titanium & Inconel
Finish: High temp black Cerakote
Website: www.gemtech.com
MSRP: $1099

This is the ONE suppressor to go to for any application you could want. GEMTECH has answered customer demand with our newest addition to our Extreme Duty line. With caliber ratings from short 5.56 full-auto to 300WM, it’s the only rifle suppressor you’ll ever need. Made of Titanium and Inconel, not only does it perform to SOCOM standards, but it won’t weigh down your overall set-up. Caliber Rated: 300WM, 300BLK, 7.62 NATO, 5.56 NATO

Company: Liberty Suppressors
Model: Cosmic
Caliber: 45 ACP
Length: 8 “ (Suppressor Module Only)
Diameter: 1.375”
Weight: 9.5 oz
Factory Tested Sound Reduction: 22-24 dB Reduction
Materials: Stainless / Titanium
Finish: Type C Cerakote
Website: www.libertycans.net
MSRP: $799

Liberty Suppressors is a family owned company specializing in making some of the quietest suppressors on the market. Quality coupled with the best customer service in the industry is what we do best. The Cosmic is no exception, with great suppression and rated for over 70 calibers, Liberty has set a new benchmark in the industry.

Company: EliteIron
Model: BATTLEDOG
Caliber: .308
Length: 6”
Diameter: 1.625”
Weight: 16oz
Factory Tested Sound Reduction: 28db
Materials: 17- 4 Stainless Steel
Finish: Cerakote
Website: www.eliteiron.com
MSRP: $760

From today’s need for lighter, stronger suppressor systems comes the EliteIron BATTLEDOG. Each suppressor comes as a 3-piece system to include muzzle brake and cover cap for thread protection which also acts as a blast mitigation device when shooting unsuppressed. Each BATTLEDOG is meticulously hand assembled and TIG welded for incredible strength and reliability. Advancements in material and technology make the BATTLEDOG truly full-auto rated. Putting an end to all the noise about suppressors.

Company: SRT Arms
Model: Shadow XL TI
Caliber: 7.62 NATO / 308
Length: 9.3”
Diameter: 1.5”
Weight: 16 oz
Factory Tested Sound Reduction: 34 db on 16” barrel .308, 33 db on 20” barrel 300 Win Mag.
Rated for: .308, 30-.06, 300 MW, .300 UM, 30/338, and any smaller calibers than .30.
Materials: 6Al-4V Titanium with 316 stainless steel blast baffle
Finish: Cerakote
Website: www.srtarms.com

.385” baffle and endcap aperture is forgiving for minor barrel thread misalignment to bore. Patented AZTECH baffle is symmetric and does not require any “clocking” of suppressor to barrel. Any minor POI shift is always straight down from unsuppressed. Measures at 133 db absolute on .308 and 134 db on .300 Win Mag 1 meter to left of muzzle to Mil-Std 1474D. 316 Stainless blast baffle eliminates sparking that occurs from Ti blast baffles.

Company: Rugged Suppressors
Model: Surge 762
Caliber: 30 Caliber
Length: 9” – Standard Configuration / 7.5” Short Configuration
Diameter: 1.5”
Weight: 21.5oz – Standard Configuration / 17.5oz Short Configuration
Factory Tested Sound Reduction: 133.4 – 138.4dB – .308; 131.5 – 137.3db – 5.56;
Materials: 17-4PH Stainless Steel; Stellite Baffle Core
Finish: Cerakote
Website: www.ruggedsuppressors.com
MSRP: $1300.00 with 7.62 flash hider

Rugged Suppressors, founded in 2014 by Henry Graham and Michael Derdziak, creates innovative products that upset the industry. We’re pioneering new materials and manufacturing methods that create superior suppressors you can trust to work right the first time.

We are committed to being the best silencer manufacturer in the United States by always focusing on positive customer interactions before and after the sale, producing cosmetically and functionally superior products, and a desire to continually outpace our competition through rigorous new product development and testing.

Company: Hailey Ordnance Company
Model: AeGIS
Caliber: .22LR
Length: 17.5” (8.5” barrel, 9” suppressor)
Diameter: 0.920”
Weight: Complete integral barrel 19-24oz
Factory Tested Sound Reduction: With Ruger 10/22, 18-23dB reduction depending on ammo
Materials: SS Lothar Walther Barrel, 7075-T6 Baffles, SS or Titanium Sleeve, optional Nitrided Steel Blast Insert
Finish: CeraKote or Matte Metal
Website: www.haileyord.com
MSRP: $550-675

The AeGIS by Hailey Ordnance Company improves on the conventional integral suppressor by including a patent pending externally adjustable gas bleed system and a Nitride hardened pressed in steel blast baffle. The Adjustable gas system allows a shooter to adjust the amount of gas being bled off behind the projectile to tune the rifle for maximum velocity, maximum sound reduction or to calibrate a specific ammunition to the subsonic threshold.

Company: (SEG) Stealth Engineering Group
Model: Competition
Caliber: .223 – .308
Length: 6.75”
Diameter: 1.55”
Weight: 14.5 oz
Factory Tested Sound Reduction: 35 dB reduction average
Materials: Titanium
Finish: Any
Website: www.SEGsuppressors.com
MSRP: $847

The SEG Competition suppressor is an evolution of the only symmetrical suppressor on the market. SEG already has competition shooters switching for our accuracy, we wanted to give them even more reason. January 2016 after testing with various shooting teams, SEG released the Competition Hancock™. The result is the least amount of bullet shift and most consistent suppressor that actually suppresses. A guide hole is included for single stamp SBR pinning.

Company: (SEG) Stealth Engineering Group
Model: SURG Suppressed Upper Receiver Group (Integral)
Caliber: .223 – .300 Blackout
Length: Barrel Length 16”
Diameter: 1.55
Weight: < 5 lbs.
Factory Tested Sound Reduction: 30-40 dB
Materials: Titanium/SS
Finish: Any
Website: www.SEGsuppressors.com
MSRP: $2000

To fully understand the scope of the SURG project you must review the spec. (Suppressed Upper Receiver Group) This project will pioneer the transition for our military to integrally suppressed rifles. SEG saw this coming and has been developing the solution well before the spec was released on November 28, 2015. SOCOM has allowed us to sell this technology to the US public. Its not just an integral suppressor, much more goes into the design that makes only ours successful.

Company: SilencerCo
Model: Hybrid
Caliber: 9mm to .45–70 GOV. Full Auto Rated. Magnum Rated Up To .338, Lapua Magnum with 18” Barrel or Longer
Length: 7.8”
Diameter: 1.565”
Weight: 13.8 oz., (with Direct Thread Mount)
Factory Tested Sound Reduction: 125.7 dB to 140.6 dB
Finish: Grey Cerakote
Website: www.silencerco.com
MSRP: $999.00

The Hybrid™ is the silencer for any platform. Compatible with calibers ranging from 5.56mm to 9mm, .45–70 GOV to .458 SOCOM, and many in between, the Hybrid is both full auto and magnum-rated and can be used on pistols, rifles, and submachine guns. Boasting low-120 dB’s on 300BLK and remaining hearing-safe with .45–70, the Hybrid offers an unparalleled pairing of versatility and performance – a combination you’ve come to expect from SilencerCo products.

The Hybrid is rated down to 16? barrels for .45–70 and .458 SOCOM and down to 18? barrels for all magnum calibers up to .338. With a slew of compatible accessories available, you can turn the Hybrid into the perfect silencer for any demand.

Company: Yankee Hill Machine
Model: Phantom, Ultra Light Tactical (YHM-4300s)
Caliber: 30 Cal (.17 HMR through .308 Winchester.)
Length: 7.625”
Diameter: 1.6”
Weight: 13 Oz.
Factory Tested Sound Reduction: -32 dB
Materials: Grade 9 Titanium with Heat Treated Inconel Blast Baffle
Finish: Natural Titanium or Black Cerakote®
Website: http://yhm.net/30-cal-ultra-light-tactical-2067.html
MSRP: $1130.00

YHM .30 Cal Phantom Tis are light enough to leave on your rifle while navigating your environment, and are equally effective for Close Quarters situations or long-range shots. All models in the series are full-auto rated, and downward compatible to YHM 5.56 Quick Detach mounts, for fast redeployment on another host firearm. Choose from Titanium or Black Titanium, Direct Thread or Q.D. Mount.

Company: Yankee Hill Machine
Model: Sidewinder, 9mm (YHM-3240)
Caliber: Available in 9mm, .40Cal and .45 Cal
Length: 7.8”
Diameter: .375”
Weight: 10 Oz.
Factory Tested Sound Reduction: -36 dB
Materials: Aircraft Grade Aluminum and Stainless Steel Components
Finish: Matte Black Plated
Website: http://yhm.net/9mm-sidewinder-sound-suppressor.html
MSRP: $699.00

YHM’s 9mm Sidewinder is the new standard in pistol caliber suppression. Many special features work together to keep weight down while offering Hearing Safe decibel reduction. The Sidewinder is constructed of Aircraft Grade Aluminum Tube and Baffle and 17-4 Stainless Steel mounting and wear components. This combination of materials creates a durable, dependable and cost-effective solution to any shooter. A 300 BLK adapter is sold separately to allow the operator to fire 300 BLK Subsonic loads through the YHM Sidewinder Suppressor on fixed barrel rifles. The Sidewinder is also rated for autofire
and use on SMGs.

Company: AWC Silencers
Model: THOR PSR
Caliber: .308 – .338
Length: 8”
Diameter: 1.625”
Weight: 18.6oz
Factory Tested Sound Reduction: -32db – -34db (MIL-STD Testing on Surgeon Rifles CSR in .308 with 16” Barrel)
Materials: Titanium
Finish: Matte Cerakote
MSRP: $1095

Designed for elite US Military users, the THOR PSR over-the-muzzlebrake suppressor was engineered by AWC in partnership with Surgeon Rifles. The suppressor mounts over the included muzzle brake for a faster attachment method that maintains the accuracy and repeatability of traditional direct-thread suppressors.

Company: Tactical Solutions
Model: Ascent22
Caliber: .22LR, .22 WMR, .17HM2, .17HMR
Length: 5.9”
Diameter: 1.0”
Weight: 4.1oz
Factory Tested Sound Reduction: 38dB
Materials: 6AL-4V Titanium, 6061-T6 Aluminum, 304 Stainless
Finish: Matte Black Anodize
Website: www.tacticalsol.com
MSRP: $360.00

New for 2016 is Tactical Solutions lightweight and versatile rimfire Ascent22 suppressor. This user serviceable suppressor is designed with our patented split tube that makes cleaning the suppressor extremely easy. The Ascent22 features DiamonDyze™ coated baffles, a titanium thread adapter and blast baffle for increased heat and wear resistance. Please visit us at www.tacticalsol.com

Company: Surefire, LLC
Model: SOCOM556-RC2
Caliber: 5.56 mm
Length: 6.2”
Diameter: 1.5”
Weight: 17 oz.
Factory Tested Sound Reduction: 136 dB on Mk18 10.5” using 70g ammunition
Materials: High Temp Alloy & Stainless Steel
Finish: Cerakote (Black or Dark Earth)
Website: www.surefire.com
MSRP: $1095.00

The new and improved SureFire SOCOM556-RC2 Fast-Attach® suppressor is the most advanced 5.56 mm rifle suppressor ever made. Compact and lightweight, our SOCOM suppressor was selected for the Mk18 and M4 by US Special Operations Command as first among all competitors in the most extensive and rigorous suppressor evaluation in history. This test covered all aspects of suppressor performance, and SureFire beat every other entry. It has also received the USSOCOM official safety verification in support of fielding. Constructed of advanced high-temperature alloys and stainless steel, the SOCOM556-RC2 features a more advanced internal venting to reduce back pressure, reducing the suppressed cyclic rate and gas blowback on the operator. The new design also includes an integrated blast shield in the back section that increases durability. The patent-pending front-plate design along with proprietary improvement in gas-flow dynamics nearly eliminates first-round flash, a true technological breakthrough in this area. It also attenuates noise and dust signatures to an unprecedented degree. A new indexing system and computer controlled welding means this suppressor securely mounts to a SureFire muzzle brake or flash hider even more solidly than our previous models, and is easier to remove after extended firing since the index tab is in a low carbon-buildup area. Like all SureFire Fast-Attach models the SOCOM556-RC2 produces minimal, consistent shift in point of impact compared with the unsuppressed weapon.

Company: FA Machine Works
Model: Grenadier
Caliber: 9mm / 45 ACP
Length: 6.8” / 7.4” / 8.5”
Diameter: 1.375”
Weight: 9.9 oz. / 10.3 oz. / 11.4 oz.
Factory Tested Sound Reduction: 32db – 38db
Materials: Titanium
Finish: Cerakote (Black or FDE) or Natural
Website: www.famachineworks.com
MSRP: $905.00 / $930.00 / $980.00

FA Machine Works Grenadier centerfire pistol suppressors are composed of titanium. Their light weight and extreme durability create a revolution in the suppressor industry. TBT (Total Breakdown Technology) provides complete serviceability with common tools and user configurable baffles with patent pending GIT (Gas Indexing Technology) enhance the revolutionary design. The Grenadier 9, Grenadier 9 CQB, and Grenadier 45 suppressors have multi-caliber capability and select caliber full auto rating that provide from 32-38db sound reduction collectively.

Company: Sturm, Ruger & Co., Inc.
Model: Silent-SR 22 LR Suppressor
Caliber: 22 LR, 22 WMR, and .17 HMR
Length: 5.37”
Diameter: 1.06”
Weight: 6.3 oz.
Factory Tested Sound Reduction: 40 dB to 113.3 on Bolt Action .22 LR
Materials: Titanium, 17-4 Stainless Steel, & Aluminum
Finish: Matte Black Cerakote
Website: www.Ruger.com/Silent-SR
MSRP: $449

Ruger has built great threaded rimfire firearms for years, and now offers a great silencer to match. The Silent-SR™ features best-in-class materials and advanced design, resulting in a light, compact and quiet suppressor. Each piece snaps together to seal the baffles making it easy to disassemble and clean. The Ruger® Silent-SR™ utilizes a titanium tube, aluminum rear cap, and stainless steel threaded mount, baffles and front cap. Go to www.ruger.com for more information.

Company: Barrett
Model: AM30
Caliber: 30 and less
Length: 8.3”
Diameter: 1.5”
Weight: .775 lbs
Factory Tested Sound Reduction: -25-30 dB
Materials: Titanium Alloy
Finish: Cerakote
Website: http://barrett.net
MSRP: $1151

Model: AM338
Caliber: 338 and less
Length: 9.9”
Diameter: 1.75”
Weight: 1.29 lbs
Factory Tested Sound Reduction: -23-28 dB
Materials: Titanium Alloy
Finish: Cerakote
MSRP: $1530

Model: DC30
Caliber: 30 and less
Length: 8.3”
Diameter: 1.5”
Weight: .775 lbs
Factory Tested Sound Reduction: -25-30 dB
Materials: Titanium Alloy
Finish: Cerakote
MSRP: $1151

Model: DC338
Caliber: 338 and less
Length: 9.9”
Diameter: 1.75”
Weight: 1.29 lbs
Factory Tested Sound Reduction: -23-28 dB
Materials: Titanium Alloy
Finish: Cerakote
MSRP: $1530

Barrett is the world leader in large-caliber rifle design and manufacturing. Well-known for .50 caliber rifles, the company now produces rifles in .416 Barrett, .338 LM, .308 WM, .300 Win, .338 NM, 7mm Rem Mag, .260 Rem, 6.5 Creed, 5.56 NATO, 6.8 SPC and .300 Blackout calibers, and is a growing innovator in the design and production of accessories for long-range shooters.

Company: MackBrothers
Model: Helium
Caliber: 7.62
Length: 7”, 8” and 8.9” depending on configuration.
Diameter: 1.52 inches
Weight: 13 oz, 13.5 oz and 15 oz depending on configuration.
Sound reduction: 32 to 34 db
Materials: Titanium, 17- 4 stainless
Finish: Cerakote
Website: Macbros.com
MSRP: $1250.00

Mack Brothers was founded in 1997 to meet the needs of the business within the firearms community. We have supplied various military and firearms manufacturers worldwide.Having a serious interest in sound suppressors we have put together products that we are very proud of. Lifelong sportsmen of South Dakota we know what it takes for products to survive in the field.

The TranQuilo M308 was designed for precision .308 rifles with a 5/8-24 threaded muzzle (1/2-28 adapters also available). The internal design redirects blowback, reducing dangerous back-pressure materials and contaminants that typically encounter the user’s face. An open, angled, four-prong flash-reducing tip reduces muzzle flash. The Muzzle-Brake Adapter is also 17-4 Stainless Steel, featuring a dual-shouldered design seating the suppressor in perfect alignment to the bore, eliminating gas from escaping to the rear of the suppressor.

Company: LaRue Tactical
Model: TranQuilo Corto
Caliber: 308
Length: 6.125”
Diameter: 1.50”-1.75”
Weight: 16 oz
Sound Reduction: Not Available
Materials: 17-4 PH Stainless Steel and Incoloy A-286
Finish: 17-4 PH Stainless Steel
MSRP: $499.00

Model: TranQuilo M308
Caliber: 308
Length: 8.0”
Diameter: 1.50”-1.75”
Weight: 23 oz
Sound Reduction: Not Available
Materials: 17-4 PH Stainless Steel and Incoloy A-286
Finish: 17-4 PH Stainless Steel
Website: www.larue.com
MSRP: $699.00

The TranQuilo Corto is a shortened version of the M308, intended for use on 300 Blackout and 5.56 SBR’s (5/8-24 and 1/2-28 adapters available). Like the M308, the internal design redirects blowback, reducing dangerous back-pressure materials and contaminants that typically encounter the user’s face. The adapter is 17-4 Stainless Steel, featuring a dual-shouldered design seating the suppressor in perfect alignment to the bore, eliminating gas from escaping to the rear of the suppressor.

Company: Thompson Machine
Model: 30Ti
Caliber: 7.62mm
Length: 8.375”
Diameter: 1.48”
Weight: 17oz
Db Reduction: 31db
Material: Titanium and Stainless
Finish: Matte Ti
Web: www.ThompsonMachine.net
MSRP: $1095

The Thompson Machine 30Ti stands out in the centerfire rifle suppressor market. While Titanium construction has become common in recent years in sealed rifle suppressors, Thompson Machine set the 30Ti apart by designing it as a take-apart suppressor for easy cleaning and inspection of its Monocore baffle stack. Constructed of grades 5 and 9 Titanium and stainless steel, the 30Ti is quiet, light, rugged, and user-serviceable.

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.

Weighing in at only 7.2 ounces including the recoil device, with a diameter of only 1.25 inches, the Gemtech Tundra more resembles a rimfire suppressor than a 9mm suppressor. If it first seems a little small for the task at hand, any initial skepticism is overcome as soon as the first round is fired.

The suppressor we received for testing and evaluation was mounted on a Glock Model 17 as a host firearm. Since the factory Glock 17 doesn’t have a threaded barrel we consulted with Lone Wolf Distributors of Oldtown, Idaho, USA. A threaded, drop-in replacement stainless steel barrel was selected and installed. Lone Wolf is one of the few Gemtech recommended barrel manufacturers for suppressor mounting.

Even with the tiny diameter of the suppressor, the factory sights are still slightly obstructed. With very little practice the factory sights can still be used with great effectiveness due to the low profile of the Tundra but we chose to mount a Green Lasermax Unimax laser sight to the factory rail in front of the trigger-guard on the pistol. The combination of the laser and the factory sights make fast target acquisition a simple process.

The Gemtech Tundra is manufactured from high tensile aluminum and finished in either a Flat Dark Earth (FDE) tan hardcoat anodized finish or the standard black hardcoat anodized finish. Both are YAG-Laser engraved for fast identification.

The Gemtech LID-8

One of the most visually distinguishing characteristics of the Gemtech Tundra is the “divoted” grip-area at the rear of the suppressor, which resembles the pattern on a golf ball. This section is machined to allow users the ability to tighten or adjust the suppressor with heavy gloves or in wet or slippery conditions. This grip-area is directly in front of (toward the muzzle) the Linear Inertial Decoupler (LID-8).

Since many semiautomatic firearms are based on the Browning design where the barrel tilts on unlocking, it has historically been a challenge to overcome the extra weight and tension placed on the end of the barrel by installing a suppressor. As finicky as some of these firearms can be with specific types of ammunition, magazines, springs, or even heavy use or poor maintenance, something attached to the barrel itself can be a big factor to maintain reliability.

In the past, recoil boosters, often referred to as Neilson Devices, have been used to counter the additional weight and drag created by adding a suppressor to the barrel of this particular firearm design. The Neilson Device is used to increase the recoil energy of the firearm to “force” everything back into alignment and function properly. It accomplishes this task by utilizing a “piston” on the end of the barrel and acting like hammer. Although these have worked well for several applications, when not properly installed or correctly “tuned”, the additional recoil has the ability to damage the firearm.

The Gemtech LID-8 uses a different principal to aid in overcoming the additional weight and mass of the suppressor. Without the aid of a piston or a necessary “hammering” to keep everything in alignment, the LID-8 actually allows the suppressor to momentarily free-float after firing, and disconnect from the inertia during the unlocking and locking sequence.

Although the function of the LID-8 is extremely effective and sounds quite complicated, the mechanism is simple to use and maintain, and even offers an additional advantage; The LID-8 can be indexed with absolutely no tools to fine-tune the accuracy of the pistol/suppressor combination. Since adding sound suppressors to a barrel (or adding any muzzle devices for that matter) have the ability to affect the point of impact, it creates a situation where a firearm may need additional sight adjustment when the device is added. In extreme cases the point of impact shift can be so severe that a different point of aim is necessary to compensate for it.

To fine-tune the relationship between the Tundra suppressor and the host pistol all you need to do is fire a small test group and note the point of impact. If it is not the same as the point of aim drop the magazine, clear the chamber and make certain the pistol is unloaded. While holding the pistol with one hand, lightly pull the Tundra grip surface away from the pistol about 1/4 inch and rotate 1 click while slowly releasing the grip on the suppressor. The suppressor can be rotated in either direction. Load, fire a test group and make notation of the point of impact. Continue this process until you achieve the desired point of impact. We fine-tuned the Tundra suppressor to the same point of impact as it shot without the suppressor and removed and replaced the suppressor while retaining the same zero.

Ammunition

While the effectiveness of a suppressor is truly realized when used with subsonic ammunition, we opted to shoot two popular types of ammunition during our testing. The first was the standard commercially available Winchester 115-grain FMJ, which represents a popular round, used by recreational shooters or heavy shooters where a budget is a factor. Often available in 100-round bulk packs it functions well in most pistols and is reasonably priced. Since it is not a subsonic round it is not nearly as quiet as the heavier ammunition, but we found it to function without failure and firing with the absence of hearing protection was comfortable and well below the threshold of pain. The second type of ammunition utilized was standard 147-grain Federal Hydra-Shock. We wanted to test the effectiveness of a truly subsonic round as well as the performance and function of this popular hollow-point. It was extremely quiet and also functioned without failure of any type. The Tundra was tested both “dry” (as designed for) and “wet” by adding a commercial available suppressor coolant. Performance in every capacity was exceptional with both methods.

Conclusion

The Gemtech Tundra is not only well designed and effective; it is small and light enough to keep the end user quite aware of its exceptional performance. It is well balanced, and comfortable when mounted, and the ability to index the Gemtech LID-8 for additional fine-tuned accuracy only adds to an already impressive system. The fact that no tools are necessary for disassembly, maintenance, cleaning or even changing the LID-8 for different firearms is a big benefit that should not be overlooked. With all ammunition used, both wet and dry, everyone present who had the opportunity to test the Gemtech Tundra expressed it was a positive experience. After handling the Gemtech Tundra it is no surprise that it has already been purchased and placed in use by the U.S. Army and other government agencies. Although we chose a Glock Model 17 for our testing platform, the Tundra is available for Beretta, Smith & Wesson M&P, SIGs, HKs and other popular combat handguns. No matter what your capacity or necessity for a compact effective 9mm sound suppressor may be, it is the opinion of this writer that the Gemtech Tundra will not disappoint.

Gemtech Tundra Specifications

Caliber: 9mm Parabellum (9x19mm)
Length: 7.6 inches (193mm)
Diameter: 1.25 inches (31.75mm)
Weight: 7.2 ounces (203gr)
Materials: High tensile aluminum alloys
Finish: Matte black or FDE hardcoat anodized
Price: U.S. $699

Sound Suppressors
Gemtech
P.O. Box 140618
Boise, ID 83714
Ph: (208) 939-7222
Fax: (208) 939-7804
www.gem-tech.com

Threaded Replacement Barrels
Lone Wolf Distributors
57 Shepard Rd.
Oldtown, ID 83822
Ph: (208) 437-0612
www.lonewolfdist.com

Unimax Laser Sights
Lasermax
3495 Winton Place, Bldg. B
Rochester, NY 14623
Ph: (800) 527-3703
Fax: (585) 272-5427
www.lasermax.com

Organized and sponsored by The Small Arms Review, the 1999 Silencer Trials drew manufacturers, government personnel, scientists, and journalists from around the country to Knob Creek, Kentucky, on October 5 and 6. Even Jane’s Infantry Weapons sent their small arms editor. For only the second time in history, industry leaders came together for a rigorous testing and evaluation of both new and established products. Some folks even brought World War II and Vietnam era silencers for testing. This event was not intended to be a contest with winners and losers, but rather an opportunity for learning. Such a gathering is unprecedented in the small-arms industry, with competitors coming together in a spirit of cooperation to improve everyone’s understanding of the art. In fact, I can’t think of another industry in the United States where competitors come together in a similar show of scholarship and fraternity. I am not only impressed by the caliber of minds in the silencer industry, I am impressed by the spirit of the people within this industry.

Doug Melton of D.H. Melton Enterprises, for example, really entered into the spirit of the Trials by bringing four new untried prototype designs for his Sound Master suppressed Ruger Mark II pistol, with the intent of selecting the best for subsequent production. He didn’t try to posture before his peers by bringing a really souped-up system that was too complex or expensive for production (unlike some computer manufacturers when submitting systems to computer magazines for comparison with other brands). Melton simply brought four new ideas to see how they measured up to his currently produced design. Melton also brought a newly designed suppressed Ruger 10/22 rifle to see how it compared to his older but outstanding suppressed rifle. He exemplified the spirit shown by the other participants.

Several manufacturers took this sense of fraternal cooperation about as far as it will go, taking apart their silencers for folks to examine. Tim LaFrance of LaFrance Specialties, for example, disassembled his awesome sound suppressor for the .50 caliber Browning M2 heavy machine gun, describing at length the principals of its operation, the R&D that went into its development, and the manufacturing techniques used to carve the complex guts of the device from a solid block of titanium. Can you imagine the major players of any other industry sharing so much information with their peers? I must confess that I really admire these guys as people as well as suppressor designers.

In fact, a lot of exceptional folks made the very ambitious SAR’s 1999 Silencer Trials possible. Everyone pitched in where needed, making this very much a grass-roots effort with a proverbial “cast of thousands.” Dan Shea, the general manager of The Small Arms Review undertook the considerable task of overseeing the event, with Joanne French from SAR organizing all aspects of the event . Dr. Philip Dater, Dan Shea and myself worked out the sound testing regimen. Stan Andrewski worked out the testing regimen for accuracy, with LMO supplying the Ransom Rest. Jeff Hoffman of Black Hills Ammunition donated all of the centerfire ammo used for testing. Two physicists, Drs. Chris Luchini and Reagan Cole, brought the necessary equipment to record pressure versus time data as well as frequency data, providing a whole new level of performance analysis.

So much was going on at once that it took a lot of folks working together like symphony musicians to orchestrate the complex flow of the event. Dan Shea was the conductor, making sure that every player knew what to do when. I was the producer, making sure everyone followed the script and making sure we maintained quality control throughout the data-gathering process. We had five people involved with gathering and recording sound data, two people at any given time handling the shooting and proper alignment of the suppressed firearms (under the leadership of Matt Smith), one person handling the chronograph (three different people shared this assignment), one person moving the firearms from a supervised storage area in the shade to the sound-testing station and thence to the accuracy-testing station, another person handling the movement of data sheets with the weapon and the filling out of duplex targets (one registered behind the other, so both SAR and the manufacturer each got identical witnessed targets for their records), and one person taking the appropriate ammunition from shaded storage to the shooting position.

Another cast of characters took over during the accuracy phase of the testing. The entire process seemed rather like a running of the gauntlet—a trial by ordeal—to those of us immersed in the frenetic nuts and bolts of the event. Occasional hiccups in the process did occur, but the impressive esprit de corps among the participants made working through the occasional problem as graceful as possible. I was quite impressed by the enthusiasm, flexibility and grace of the participants working under difficult technical, logistic and time constraints.

Why go to so much trouble and expense and heartburn? It is true that impartial observers can provide a reasonably satisfactory subjective comparison of suppressor performance when several silencers are compared side by side on the same day. This is how the British National Physical Laboratory compared silencer performance during World War II. Even rigorously conducted subjective comparisons have their limitations, however.

Subjective comparisons can differ substantially depending on an individual’s ability to perceive different frequencies. People who have lost their ability to hear high-frequency sounds, such as an old gunnery sergeant exposed to years of intense impulse noise, might evaluate suppressors quite differently than someone with a normal frequency response. Consider, for example, two suppressors that eliminate different frequencies and yet produce the same peak sound pressure level (abbreviated SPL). For people with normal hearing, the suppressor that is especially good at eliminating the higher frequencies of a suppressed gunshot will seem quieter than the suppressor that eliminates predominantly lower frequencies. The gunny would prefer the suppressor that was better at eliminating low-frequency sound (since he can’t hear the higher frequencies anyway).

There are other limitations to subjective testing. The system breaks down if many suppressors must be compared; it’s just too hard for any person to keep track of too much sensory input. (Ask, for example, any modern fighter pilot about sensory overload in the cockpit during combat.) Then there is the problem of how to describe one’s subjective impression of sound signatures. Descriptions such as “pop” and “whoosh” don’t really convey any useful information, nor do descriptive words conjure up the same mental image to everyone.

Measuring the actual amount of sound pressure produced by a suppressed gunshot and converting the data to a simple scale that mimics the subjective impression of the human ear (the decibel scale) provides a rigorous and objective benchmark that can be compared to benchmarks such as the threshold of human hearing and other sounds of known intensity. Any number of samples can be compared. The decibel reading of the sound pressure level isn’t the whole story, but the SPL represents the most objective single data point suitable for measuring how quiet a suppressed gunshot is. The SPL in decibels also provides the means for comparing that suppressed gunshot to any number of other suppressed gunshots and as well as to the same firearm without a sound suppressor.

Gathering the data for such evaluations is time-consuming. I normally evaluate just two or three suppressors during a typical day at the range, when I’m working by myself. Testing scores of suppressors on the same day required a lot of organization, specialized equipment, and—most of all—help from a lot of enthusiastic people.

In terms of the aforementioned equipment, we used two precision impulse meters: a Brüel and Kjaer Model 2209 Impulse Precision Sound meter with a B&K Type 4136 1/4 inch pressure type microphone; and a Larson Davis Model 800-B meter with Model 2530-1133 random incidence microphone. The meters were set to Peak Hold and “A” weighting, with the microphones placed 1.00 meter to the left of the muzzle or front of the sound suppressor. Time domain and frequency domain data were collected using a computerized digital recording oscilloscope built by Dr. Reagan Cole; this system also used a B&K Type 4136 1/4 inch pressure type microphone. Projectile velocities were measured using a P.A.C.T. MKIII timer/chronograph with MKV skyscreens set 24.0 inches apart and the start screen 8.0 feet from the muzzle, and hard copies of the data were printed after each string using a Hewlett-Packard Model 82240B battery-powered printer via infrared data link.

Accuracy testing was conducted to look for design flaws. One of my own suppressed Ruger Mark II pistols, for example, only delivers 4+ inch groups at 25 yards and the projectiles leave oval holes in a target (suggesting extreme bullet yaw), while another suppressed Mark II that I own delivers 1/4 inch groups and perfectly round holes at the same distance. Since these pistols exhibit a ten-fold difference in accuracy, clearly one manufacturer is doing something right, while the other is doing something very wrong. The accuracy testing phase of the 1999 Silencer Trials was intended to reveal such disparities.

Ransom Rests were used for the accuracy phase of the testing, and here the manufacturers or owners of the suppressed firearm were allowed to do the shooting so that they could be confident that the results were as good as possible. Sandbags were used if Ransom did not offer a pistol adaptor for a given handgun.

Stan Andrewski handled the accuracy testing at the trials. The manufacturer removed the pistol grips, and Andrewski mounted the pistol in the machine rest. When the manufacturer was happy with the adjustments, the manufacturer himself would then do the shooting. While the Ransom Pistol Rest is a true machine rest, the rifle rest still depends upon shooter skill. Therefore, manufacturers were allowed to nominate a designated shooter, and a number of them opted for this approach. Mark White of Sound Technology frequently served as the designated shooter, which was a tribute both to his shooting ability and the to respect of his peers. No one seemed to worry that he might do less than his best when shooting a competitor’s system. In fact, White shot a one-hole group using Black Hills .44 Specials with the suppressed Ruger 77/44 rifle made by John’s Guns. Folks were so impressed by the sound reduction and accuracy of this system that three people ordered a rifle from John Tibbetts on the spot.

What about the specific results of the testing? We’re still working on data analysis, which will be published in book form by Moose Lake Publishing LLC, the parent company of The Small Arms Review. We’ll include a brief history of each company, sound and velocity data, detailed descriptions of silencers and integrally silenced guns (including length, diameter, weight, and construction details), plus a photo of each item being tested, as well as the test target used to determine system accuracy. Drs. Chris Luchini and Reagan Cole will contribute a chapter on their frequency and time-domain analyses, Dr. Philip Dater will contribute a chapter on testing methodology and using sound suppressors as hearing protection devices, and Mark White will contribute a chapter on the latest developments in subsonic ammunition for centerfire rifles, including an evaluation of the subsonic 7.62x51mm ammunition from Black Hills Ammunition and Engel Ballistics Research. We’ll also provide a discussion that will try to synthesize all of the data into simple-to-digest conclusions.

We’re also trying to work out some new quantitative ways to compare systems, such as using a plot to compare sound reductions versus velocities generated by integrally suppressed guns, and we may be able to incorporate price versus performance analyses as well. I’m working with several established scientists and engineers to develop meaningful new ways for comparing system performance in easily digested ways. This will take several more months of work. Publication of the book will be reported in a future issue of The Small Arms Review.

For the moment, the bottom line for me is that I was impressed by the state of the art exhibited by all of the participants. Performance that was unthinkable just a few years ago is now commonplace. It was a real privilege to study so many outstanding products, and that study has just begun. My heartfelt thanks go out to the many folks from throughout the industry who made this stimulating and historic event possible. We will all learn a great deal from this considerable effort.
Participating Manufacturers

Black Hills Ammunition, Inc., P.O. Box 3090, Rapid City, SD 57709-3090; phone 605-348-5150; fax 605-348-9827

CCF/Swiss, Inc., P.O. Box 29009, Richmond, VA 29009; phone 804-740-4926; fax 804-740-9599; URL http://www.ccfa.com

D.H. Melton Company, Inc., 1739 E. Broadway Road, Suite 1-161, Tempe, AZ 85282; phone 480-967-6218; fax 480-902-0783

Don Austin Wagenknecht, 12400 Blue Ridge Blvd., Grandview, MO 64030; phone 816-765-2539; fax 913-829-6999; e-mail daw@sprintmail.com

Engel Ballistic Research, 544A Alum Creek Road, Smithville, TX 78957; 512-360-5327; fax 512-360-2652

Gemtech, P.O. Box 3538, Boise, ID 83703; phone 208-939-7222; fax 208-939-7804; URL http://www.gem-tech.com

J.M.B. Distribution, 4291 Valley Quail Street, Westerville, OH 43081; phone 614-891-5784; e-mail JBurg@mailbox.iwaynet.net

John’s Guns, 3010A Hwy. 155 N., Palestine, TX 75801; phone 903-729-8251; fax 903-723-4653

LaFrance Specialties, P.O. Box 178211, San Diego, CA 92177; phone 619-293-3373; URL http://www.NAIT.com/LaFrance

S&H Arms of Oklahoma, P.O. Box 121, Owasso, OK 74055; phone 918-272-9894; fax 918-272-9898

Serbu Firearms, 6001 Johns Road, Suite 511, Tampa, FL 33634; phone 813-854-1532

Sound Technology, P.O. Box 391, Pelham, AL 35124; phone 205-664-5860; e-mail rem700p@sprintmail.com; URL http://www.hypercon/soundtech

Special Op’s Shop, P.O. Box 978, Madisonville, TN 37354; phone 423-442-7180; URL www.compfxnet.com/opshop

Summers Machine Enterprises, 1303 Pauls Airport Road, Thomasville, NC 27360; phone and fax 336-472-6394; e-mail badgerf4@aol.com

TBA Suppressors, 10998 Leadbetter Road, Ashland, VA 23005; phone and fax 804-550-3159; e-mail TBASuppressors@erols.com

Urbach Precision Mfg., 1529 Axe Drive, Garland, TX 75041; phone 972-864-0848; fax 972-864-0571

Young Manufacturing, Inc., 5621 N. 53rd Avenue, Glendale AZ 85301-6011; phone 623-915-3889; fax 623-915-3746; e-mail sales@newriverarms.com, URL http://www.newriverarms.com

MK 23 SUPPRESSOR DEVELOPMENT: THE TRANSITION FROM THE COLT TO THE H&K PISTOL

Your faithful correspondent recently had the opportunity to view the genesis of the Offensive Handgun Suppressor by Knight’s Armament Company (KAC). While there is much talk about the newly adopted suppressor and its amazing performance, little is ever shown of exactly “What” makes it function so well. The new system adopted by USSOCOM was an engineering challenge of the first order, and KAC spent over $250,000 and 18 months in the development process. SAR contributor Doug Olson was Chief Engineer on the project, and I managed to talk him into telling the story himself. We hope you enjoy this SAR exclusive look not only into this amazing suppressor, but the intense process that goes into filling a U.S. government firearm procurement.

The development of the Suppressor for the Mk 23 USSOCOM Pistol was a huge challenge. The U.S. Government’s desires for the Suppressor’s performance far exceeded anything that had ever been accomplished commercially. The initial development contracts were released in 1991: one to Colt’s Firearms with Knight’s Armament developing the suppressor and one to H&K with their own suppressor design. The state of the art at that time was the Qual-A-Tec/AWC Technology produced Nexus 45 for the M1911 Colt. That 1991 suppressor only delivered approximately 18db reduction, wet. That was a long way from the 30db dry that the Government was seeking. KAC went through a 12-month development process that resulted in delivery of suppressors for the Colt OHG that in Government tests averaged 28.8db reduction with M1911 ball and 26.6db reduction with +P. The H&K suppressor averaged 22.2db reduction with M1911 ball and 15.2db with +P. That was only part of the story because the KAC suppressor yielded an incredible 36db reduction when water was added to the suppressor. It was obvious why the Government wanted to have the KAC suppressor attached to the superior H&K weapon. That was a very impressive advance in the state-of-the-art in a relatively short time frame.

The Government initially decided that surely KAC could easily convert the design from the Colt’s Pistol to the H&K Pistol with no additional development expenditure and thus decided it would not fund any additional development effort. That erroneous situation was finally corrected and late in 1994 KAC was issued a contract to change its suppressor design to fit the H&K weapon.

The task proved to be a more formidable challenge then even KAC had anticipated. The suppressor for the Colt pistol was attached directly to the frame of the weapon. That meant that the Suppressor for the Colt pistol did not need a booster to force the weapon to function with the additional weight of the suppressor. The job was now to adapt the suppressor to a gun that required a booster, while keeping the performance of the original suppressor.

One area of the suppressor that many still do not understand is how the recoil regulator (booster) works. This is sometimes referred to as a “Nielsen device”. Based on many years of experience with the system, the following will try to explain its function. If one were to mount a conventional suppressor to the barrel of a pistol that uses a short recoil mechanism (like the M1911 or H&K OHG) one would immediately find that the weapon would not cycle semi-automatically. That is because the suppressor mass was added to that of the barrel and slide putting the total mass beyond the design limits of the gun. One could of course reduce the mass of the barrel and slide and change the recoil spring to achieve proper functioning with the suppressed pistol. The problem would be shifted to cycling of the converted pistol without the suppressor. The low slide and barrel mass would result in increased velocities of the parts and the gun would have a greatly reduced service life and increase the risk to the shooter of the slide coming off the back of the gun after firing. Neither of these situations is acceptable.

What then is the solution? It is to allow the mass of the suppressor to move independently of the barrel and slide until after the slide is unlocked from the barrel. A piston is added to the back of the suppressor that attaches to the barrel. The suppressor is thus allowed to move forward along the axis of the piston against a spring load. The propellant gasses that enter the suppressor work to apply a force to the piston head tending to drive it along with the barrel and slide to the rear while driving the rest of the suppressor forward. This “equal and opposite reaction” against the barrel makes the weapon function more or less normally.

What must happen is that the suppressor must reach the end of its stroke AFTER the barrel becomes unlocked from the slide. It is easy to imagine the shock that the barrel sees when the suppressor reaches the end of its stroke. As they say “timing is everything”. Much work was done to make sure the suppressor matches the weapon to provide for equal weapon life with and without the suppressor. Hundreds of thousands of rounds were fired throughout the development and test cycles of the weapon and suppressor.

That also means that a recoil regulator for one type of weapon may not work on another type. That was exactly the situation KAC ran into with trying to adapt the OHG Suppressor onto the smaller H&K USP and Glock pistols. The relative slide and barrel mass of these weapons was, from a dynamics standpoint, very different from that of the OHG. The Tactical pistol’s slide only lived 300 rounds when the OHG suppressor was first tested on the gun. To prevent that from happening, H&K changed the barrel threads from right hand to left hand to prevent the OHG suppressor from inadvertently being fired on the Tactical gun. H&K ran an exhaustive test and developed a special modification to the piston, regulator spring and buffer that provided proper functioning with the Tactical. KAC has built its commercial Tactical suppressors with those modifications and even with springs provided by H&K. It is of note that very few rounds fired from the wrong regulator setup can ruin a gun. It is also interesting to note that the lighter slide and barrels reduces the efficiency of the suppressor and results in a sound pressure level reduction of 3db less.

One of the problems the first generation H&K suppressor displayed was that it loosened from the barrel. When this happened bullet strikes were noted inside of the suppressor and accuracy was lost. The culprit was traced to the barrel to suppressor interface. The interface for the suppressor onto the barrel had to be changed to provide for additional stability. The first generation H&K OHG had threads at the end of the barrel with a single diameter behind the threads to support and align the suppressor. KAC had the interface changed to have two bearing surfaces, one behind the threads and one in front of the threads that provided support at both ends of the interface. Because the pistol itself was so long, H&K could not allow any more length of engagement between the suppressor and the barrel. That meant that the allowable tolerance with which the two diameters on the barrel and the two bores within the piston had to be reduced to keep the allowable misalignment at the end of the suppressor to acceptable limits. Both bores within the piston ended up with +/- .0005 tolerances. It also means that the threads no longer provided any alignment, they simply held the two parts together. An “O” ring was added within the piston that engages the front diameter on the barrel. It acts as a friction device to help keep the suppressor tight onto the barrel. The dual diameter support helps keep the alignment of the suppressor to the barrel even when the suppressor is not tight on the barrel.

When KAC first started to adapt its Suppressor for the Colt OHG to the H&K gun, one of the challenges was to make a piston for the recoil regulator to have geometry similar to the muzzle support for the Colt gun. Contrary to the initial looks, the muzzle device for the Colt gun was designed to be an effective component of the suppressor and not to be any thing special from a muzzle brake design. That muzzle device was responsible for bringing down the sound pressure level of the suppressor by a full 3 db over a straight interface.

The initial suppressor prototypes were fitted to first generation H&K guns and in order to keep the muzzle brake interface as close as possible KAC tried to move the recoil regulator springs to the outside of the can. At first it was thought that four small springs would work, then six, then ten. The small diameter and short springs just too severely limited the stroke of the piston and were finally abandoned. Moving the spring to the inside of the can exposed it to all of the contamination and heat from the propellant gas but there was no option since KAC had to keep within the size limits imposed. The piston, spring and buffer designs all went through a number of iterations before a final design was found that provided acceptable sound pressure level reduction and had proper service life.

Small changes such as increasing the length of the piston where it engages the bore of the suppressor were found to be necessary to allow easy removal and reinstallation of the piston. Since the overall length of the suppressor could not increase and the stroke of the piston could not decrease, the longer piston bearing resulted in a reduction in the total length of the baffle stack. The shorter baffle stack of course reduced the net efficiency of the can. In all the baffle stack had to be shortened by approximately 1/2 inch from that of the Colt pistol to keep the system overall length within the specification. Certainly a quieter suppressor could have been delivered if the length of the can could have been increased. On the commercial side of the suppressor business limits like this are seldom imposed. Designing a suppressor to meet a Government Specification can present a great challenge.

Another problem that KAC accidentally found was that the H&K Pistol would not tolerate any interference between the suppressor and the recoil spring guide rod. The problem is that static measurements do not show the true situation because the recoil spring assembly has a secondary buffer spring. Under dynamic loading, the guide rod can protrude further from the weapon in full recoil than was obvious when taking static measurements. What happened was the suppressor on its return to battery would just tap the end of the guide rod. That tap resulted in a broken slide. Hard to believe? We thought so too, but it happened. The dynamics of this system must be understood to achieve long weapon life.

The end result, the MK23 Suppressor, has set a new standard in suppressor technology. It has been tested with more rounds than probably any other suppressor ever built. At the 1997 Suppressor trials at Knob Creek it produced an unheard of 42db reduction with a little water in the tube (wet). That is quieter than many of the 22 caliber suppressors that were tested. The problem is we know it could have been even quieter had KAC been allowed a little more volume. But the user (USSOCOM) has an excellent piece of hardware that will see service for many years to come.

Knights Manufacturing Company

Dept. SAR
7750, 9th Street S.W.
Vero Beach, FL 32968
(561)778-3700 – Phone
(561)569-2955 – Fax

Maybe I expect too much from my .22’s – all I ask for is 1/2 MOA accuracy and quiet suppressed operation for discrete target shooting. The quest for this performance started several years ago when I purchased one of JR Customs “Navy” suppressors for my Ruger Mk II pistol and an old Glenfield .22 rifle. My decision to go with the Navy was based on its versatility and performance ratings. I wanted a suppressor that could be moved from both pistol and rifle for quiet target shooting in the woods behind my property. At the time of purchase, the Navy was highly rated for quiet operation. An excellent and very thorough Al Paulson article (MGN – June 1992) sold me on its design aspects and sound reduction capabilities. I called Jim Ryan, and he guided me through the paperwork and legal details since it was my first Class III purchase. This conversation put me at ease since all this was new to me at the time. Although many of us who read this magazine have gone through the NFA paperwork process many times, there are probably just as many who are “sitting on the fence.” Some people do have reservations for taking the plunge into the NFA world, but those who do are usually happy they did.

After acquiring the Navy, it was initially put into service with the Mk II pistol, and usually shot “wet” by spraying some oil into the can before use. This greatly enhanced the degree of suppression over shooting in the “dry” mode. One would think that this would help while in service with the rifle, but the Navy seemed to perform equally well with the rifle in either the wet or dry modes. To me, the main hindrance of this system was that optimum suppression required a recharge of oil for every magazine fired through the pistol. This required that I carry a can of oil on my person while out on shooting expeditions. Although this might not be a big deal to some, it was beginning to be a hassle to me.

Navy to Vortex-2 Conversion:

Several years went by, and it was decided to upgrade the old Glenfield rifle to a Ruger 10/22 with a match bull barrel for the enhanced accuracy I desired. A call went out to Jim Ryan to discuss threading the 10/22 rifle barrel to accept the Navy can. I mentioned to Jim that in the past I had a few problems with bullets tumbling after moving the can from rifle to pistol on occasions, and he offered to let me Form 5 the can back to him for checkout. He also offered to upgrade the Navy to his latest design. When Jim Ryan and Dr. Philip Dater joined forces, their design ideas apparently meshed, and ultimately resulted in the Navy being reconfigured into a smaller and lighter package. Gemtech’s upgraded Navy suppressor is now called the Vortex-2.

The Vortex-2 reduced the Navy’s overall length from seven to five inches, and also utilizes new internal baffle configurations. Tube diameter remained 1 inch, but overall weight decreased to a light 6.7 ounces. The original Navy weighed a hefty 12.3 ounces. According to Jim, the new design offers a sound reduction in excess of 35 dB while shot dry on a pistol when using the right ammunition. Per Al Paulson’s previous MGN article on the original Navy can, the net sound reduction with a Walther pistol was 23 dB (dry) and 39 dB (wet) using Hansen Standard Velocity ammunition. In yet another previously published article, Al retested the Vortex-2, and produced a net sound reduction of 33 dB. I consulted with Al concerning the differences between his and Jim’s data of 33 versus 35 dB. He explained that the difference is due to several variables: (a) they both used different pistols as the base weapon, and different barrel lengths and chamber dimensions can affect a suppressed weapon’s sound signature by several decibels; (b) they used different ammunition which would account for a decibel or two difference; and (c) they tested under different atmospheric conditions, which can easily affect the sound signature by a decibel. Considering all these variables, Al concluded that his and Ryan’s data agreed pretty well. Whatever the sound reduction, it is a very quiet unit when utilizing quality subsonic ammunition.

Apparently, the meshing of their designs and ideas has resulted in optimizing suppressor performance in the smallest possible package. Not only is the new unit 2 inches shorter, it provides excellent sound suppression without the need for carrying around a can of oil for quiet shooting. The Vortex-2 end caps are constructed of 300 series stainless steel. Five 6061-T6 aluminum baffles replaced the original seven 300 series stainless baffles in the Navy can. Aluminum has thermal conductivity characteristics that provide some advantages over stainless steel. Heat will transfer through aluminum faster than steel, hence helping to cool the heat spike from the muzzle blast. The new unit is designed to meet the requirements for a compact, highly corrosion resistant muzzle suppressor. The Vortex-2 is engineered so that there is no necessity for disassembly for maintenance. This unit interfaces well with virtually any .22 Rimfire weapon, both rifles and pistols. The suppressor can be quickly removed, returning the firearm to its original appearance and use in non-suppressed shooting requirements.

Rifle Modifications:

Before sending the Navy can and 10/22 barrel to Gemtech for modification, a few test sessions were in order to ensure the rifle was performing adequately. The deluxe Ruger wood stock was routed to accept the new barrel. I simply used a short section of broom handle with sandpaper wrapped around it to open up the barrel channel. A Tasco 3-9×40 TR scope was mounted to the receiver with Millet rings. I thoroughly tested the rifle to ensure that the new Wilson Match bull barrel performed as advertised. Using match grade ammunition, the rifle produced groups hovering around 1/2 inch at 50 yards. CCI Standard and RWS Subsonic Hollow Point loads easily produced sub-1 inch groups at the same distance.

After satisfying my requirement for minimum group sizes at 50 yards, I filed the ATF Form 5 to get the Navy can modified. While waiting for all of the paperwork to clear, I also took the opportunity to fine-tune the 10/22 itself. First, the trigger pack was sent to Mark White (Sound Technology) to have him work over the trigger. Mark reworked the trigger to be incredibly smooth with a release of about 2 pounds. A smooth, light trigger is probably one of the best things one can do to enhance accuracy potential of any firearm. Mark has considerable experience with 10/22 triggers, and I highly recommend his work. I also installed an extended magazine release button, and a bolt hold-open device from Brownell’s in Iowa (515-623-5401) as finishing touches.

Shooting Impressions:

After the ATF Form 5 was approved, the Navy was sent to Gemtech along with the 10/22’s bull barrel for threading. When the new unit finally made it back, I was off to the range to test out the new system. I had Jim cut the barrel back to 16.25 inches, to provide a total “barrel” length of about 21 inches with the muzzle can attached. I compared the new Vortex-2 with a friends integrally suppressed .22 rifle. It was very difficult to “hear” which gun was quietest while in the field. The efficiency of both suppressors was remarkably similar under typical field conditions. Eighteen different brands of ammunition were fired though both rifles. With high velocity ammunition, the integral rifle obviously had the edge over the Vortex-2 since muzzle velocities were being bled down to subsonic speeds. Most integral suppressors are optimized to drop high velocity ammunition to subsonic levels in order the avoid the ballistic crack. A barrel fitted with a muzzle can will produce higher velocities than are produced by the ported barrel of the integral suppressor. With subsonic ammunition, there was the perception that both units were equally quiet. Without sound measuring instruments, this is very tough to differentiate when they are that close.

As we have learned over time, subsonic ammunition will provide the quietest sound signature for target shooting and pest elimination needs. One must experiment with different brands of ammunition depending upon the firearm and the intended purpose. Outside air temperature is also a factor, as the speed of sound is more easily surpassed as temperature drops. A projectile that surpasses the speed of sound will literally wake the dead as compared to its subsonic cousin. At 32oF, the speed of sound is 1086 fps. At 82oF, the speed of sound increases to 1142 fps. My measurements of more than 500 subsonic test rounds produced an overall average velocity of 1047 fps out of the 10/22 rifle. This is an ideal velocity as it produces both an accurate, hard hitting projectile that is subsonic down to, and below the freezing mark. It will not be subsonic if fired in temperatures which approach 20oF, or colder.

Some suppressors work best with loads which produce combustion gases of a particular velocity. I have found 2 or three loads/brands which produce the best performance combination of velocity, accuracy, and quietness for my needs. Al Paulson’s previous test of this unit showed that the Vortex-2 produced better sound reductions when mounted on a pistol as opposed to a rifle. Having used the Navy for two years, and then converting, the perceived sound reduction appeared to be about the same with the rifle. When used on the pistol, it is definitely quieter. From a shooter’s subjective standpoint, the Vortex-2 shot dry is almost as quiet as the Navy shot wet, and the Vortex-2 shot dry is vastly quieter than the old Navy shot dry.

Some of the subsonic brands of ammunition that performed the best were CCI Standard, CCI Green Tag, RWS Subsonic, Lapua Scoremax, Fiocchi 300, Federal Ultra Match, and Eley Tenex. For normal plinking and target shooting, I found that CCI Standard and RWS Subsonic are tough to beat. They both provide excellent accuracy and are economical to shoot. For hunting (where allowed by law), the Lapua Scoremax is my pick due to its heavier 48 grain bullet. Federal Ultra Match should be selected for those who are serious about accuracy requirements, as they are expensive. Despite cutting the barrel back to 16.25 inches, no degradation in accuracy was encountered with the addition of the suppressor. At 50 yards, the rifle easily produces groups at, or under 1-inch with the lower priced ammunition. The high-priced ammo produces groups around 1/2 to 3/4 inches at the same distance as fired from the bench.

Although I don’t normally recommend swapping muzzle cans around on different firearms, my personal limit is two guns for one suppressor. This will ensure thread life is prolonged, as there is less of a chance that the threads will be damaged. The amount of torque applied while attaching the suppressor should remain the same each time. Also, the orientation of internal components of the suppressor should be the same every time the can is reinstalled. Although the new suppressor performed flawlessly while on the pistol, I keep the Vortex-2 dedicated to the rifle. The option for use on the pistol still remains, as I may use it in due time.

Maintenance Recommendations:

After each shooting excursion, I always spray a small amount of oil into the suppressor from the breech end of the gun, and fire a shot or two to disburse the oil throughout the can. This helps keep the unit from accumulating excessive powder residues, and will also help reduce or eliminate any corrosion concerns. I hate to clean my guns, and usually never do unless they don’t work, or if accuracy drops off dramatically. A few shots of oil at the end of a shooting session are my personal preference, but to each his own. As recommended by Mark White, a suppressed weapon should be stored with the muzzle pointing down and with the action open to allow venting so internal moisture can evaporate. I wholeheartedly second Mark’s recommendations.

External finish on the Vortex-2 as delivered was smooth and polished. I cleaned the exterior and applied two coats of spray-grit paint. This paint is an epoxy-based spray, with grit particles suspended within the solution. It is available from Brownells. This finish system has held up for two years now with no required touch-ups. It makes for a unique exterior coating, and gives just a little extra grip surface for checking that the can is secured to the barrel. I’ve even used it on a rifle scope that was scratched up beyond all recognition. The grit particles have no sharp edges so they can’t cut or abrade your hands.

Summary:

Many people get into the NFA world by purchasing a suppressed .22 firearm. A suppressed .22 pistol or rifle can provide a lot of shooting fun. The low noise and low cost of ammunition are the main benefits. The .22 can be safely and quietly fired on my 5 acres without disturbing the neighbors. I’ve set up a shooting bench behind the back yard and have backstops at 25, 50, 75, and 100 yards. If it is an unusually quiet day around my neighborhood (no wind or road noises), I just fire up the Massey-Fergeson diesel tractor and let it idle while I shoot. The tractor provides excellent background noise which completely masks any noise coming from the gun or the bullets striking the backstop. With the right ammunition, the bullet hitting the target is usually louder than the report of the rifle. Neighbors just 60 yards away never near a thing. The quiet 10/22 has been one of my favorites during shooting excursions over the last two years. It allows me to make things happen quietly at a distance.

Gemtech’s Vortex-2 is a compact and quiet performer, and is easily moved from either a rifle or pistol for those who prefer this option. When used on the Mk II pistol, its overall length comes out to around the same as a factory 10-inch bull barrel. Holsters are readily available to accommodate this barrel length. The 10/22 rifle with the match barrel is now both accurate and quiet. Although the Vortex-2 can be made to shoot even quieter on the pistol by adding a small amount of oil and shooting in the wet mode, I found the unit is quiet enough to pass on this extra task. As before the modification, this was not necessary with the rifle since it makes no perceived improvement on sound signatures.

It’s nice to find companies and individuals that stand behind their products and strive for design excellence. The Gemtech folks get my thumbs-up. If you are looking for versatility in a 22-muzzle can, and a company that backs their products 100%, the Vortex-2 might be just what you’re looking for. It provides excellent sound reducing performance in a very small package. Add an accurate rifle to the equation and the end result is one happy camper.

Sources:

Gemtech
Gemini Technologies, Inc.
P.O. Box 3538
Boise, ID 83703-0538
Phone: 208-939-7222

Sound Technology
Mark White
P.O. Box 391
Pelham, AL 35124
Phone: 205-664-5860

Brownell’s
200 South Front Street
Montezuma, IA 50171-1000
Phone: 515-623-5401

Tasco
2889 Commerce Parkway
Miramar, FL 33025
Phone: 305-591-3670