Consumer demand for user serviceable .22 LR silencers is at an all time high and Gemtech revealed two brand new .22 LR silencers at the 2010 Shot Show in Las Vegas. In this study, the Alpine and the G5-22 as well as the Outback II were tested. The Outback II was used as a reference as its one of the most popular, best selling silencers on the market today. In order to bring the reader the broadest possible spectrum for these silencers, three pistols and four rifles were used in testing. The pistols include the Walther P22, the SIG Mosquito and the Ruger MKIII with Tactical Solutions Pac-Lite upper. The four rifles used were the CZ-452, M&P15-22, Ruger 10/22, and Colt M4 with 16 inch barrel with Atchison conversion.

Facts and Myths about .22 LR silencers

It was once widely believed that user serviceable or “take down” design silencers were many decibels louder than their sealed brethren. Recent testing has shown that this is merely a myth as two of the top three .22 LR silencers tested on a pistol were take down designs. Take down designs also took the top 3 on a Ruger 10/22 as well. It was also believed that sealed up silencers never got louder as they clogged up. One school of thought was they actually got quieter when dirty. This is all nonsense and has been proven false. Each time a .22 LR round is fired, a tiny amount of molten lead and carbon adheres itself to the baffle stack, and over time the baffles simply become clogged up and cannot function properly. Much as is the case with a muffler on an automobile. Silencers that are sealed do get louder with use and if used enough will require a rebuild by the manufacturer. Host weapon, barrel length, rate of fire and other factors will dictate how fast a silencer will become clogged up and lose efficiency. Pistol and rifle use on a sealed silencer will usually allow between 10 and 15 thousand rounds to be fired before cleaning is necessary, but use on a .22 LR machine gun will cut round count to one third. I would never recommend using a sealed silencer on a .22 LR machine gun.

Gemtech Alpine

The Gemtech Alpine is manufactured from 7075 series aluminum and is hard coat anodized. The thread insert is titanium to help prevent galling. Weighing in at only 3.7 ounces one hardly notices the weight on a pistol and it’s nearly impossible to detect when used on a rifle. It doesn’t occlude the factory sights on any of the pistols tested. One of the best features of this silencer is the fact that the powder gas (which generates molten lead and carbon deposits) is not allowed to reach the outer tube. This is an ingenious design feature that makes disassembly of the silencer much easier than traditional K baffle silencers. Few other silencers on the market offer this feature. The silencer can be disassembled with a U.S. coin and a wooden dowel. I personally used a plastic writing pen to push out the stack. Reassembly after cleaning was a snap. Instructions are provided with the silencer including drawings.

Gemtech G5-22

This silencer was created to allow the end user to get the same look as a 5.56mm rated G5 on the new, popular .22 caliber AR-15 look-a-likes, such as the M&P15-22, GSG AK-47 and a number of others. The silencer comes with one quick attach mount and you can purchase others. It works exactly as the Bi-Lock does on the full sized G5. The silencer is 7075 aluminum hard coat anodized and can be disassembled for cleaning by the end user. A tool is supplied but is not required in a pinch. I disassembled the silencer without the tool without any trouble. If you don’t like the look of a 1-inch silencer on your AR-15 conversion or one of the new AR-15 .22’s then the G5-22 is a great option.

Sound Testing the Silencers

Sound testing was conducted with two Bruel & Kjaer 2209 impulse sound meters equipped with Bruel & Kjaer 4136 1/4 inch condenser microphones and calibrated with a Bruel & Kjaer 4220 pistonphone. Testing was done at two locations as per Mil-Std 1474D. One microphone was placed 15cm from the shooter’s left ear and one was placed at what is known as the “reference” location which is 1 meter to the left of the weapon’s muzzle, 1.6 meters over the ground. The reference location is more commonly used in silencer testing.

Host Weapons Tested

The Walther P22 has become the gold standard in silencer testing in recent years as it is readily available and can be adapted to accept a silencer cheaply and quickly. Adapters that fit the already threaded factory barrel are available for around $40, which represents less than half the price of a custom threaded barrel. The Ruger MKIII is a bit more pricey, but I really enjoy the feel of the weapon when equipped with the Tactical Solutions Pac Lite threaded 4.5 inch barrel. The Pac Lite is a super accurate upgrade to any Ruger pistol. The SIG Mosquito can also be adapted to accept a silencer with the correct adapter. While the Mosquito has had mixed reviews from users, I have had no problems from the weapon. The Ruger 10/22 is also the gold standard of silencer testing as they are so popular and one can either have a factory barrel threaded or one can buy any number of pre-threaded aftermarket barrels that are accurate. In this study, I used a factory barrel that I threaded. The CZ-452 is a very nice traditional bolt action .22 LR host weapon. This particular one was factory threaded and with the use of an inexpensive adapter you can affix your silencer right away. The Colt M4 used for this test has a 16 inch barreled upper and I used a drop in conversion kit that is available from a number of sources including Ceiner, CMMG, and others. The magazine used in the Colt M4 was the reliable Black Dog Machine plastic magazine designed to work with the conversion and it even has a bolt hold open feature. The M&P15-22 was also tested as the G5-22 was developed to fit this type of weapon. I threaded the barrel on this weapon myself. It needs to be understood that the general industry standard in the USA for .22 LR silencers regarding barrel thread length is around .4000″. Many factory threaded barrels that are being offered today use the .6000″+ thread length that is for flash hiders. This creates a situation that allows the silencer to be screwed to far onto the host weapon’s barrel and the barrel becomes dangerously close to the first baffle. This can seriously damage the silencer and the crown on the barrel. It is therefore highly recommended that you use a spacer to alleviate this problem when using barrels that are threaded beyond .4000″. These spacers are available from a number of sources, including www.thesilencerstore.com.

Final Impressions

At the reference location using the Walther P22 and the Ruger 10/22, the Outback II and Alpine produce virtually an identical sound signature. At the ear, the Outback II sounds quieter as shown in the charts. The G5-22 is quieter on the M4 with the Atchison conversion kit at the reference location than the M&P15-22 is. However at the ear the meter shows there is no discernible difference as one decibel is required for the human ear to notice a difference. I did find it interesting to show that the CZ-452 was considerably quieter at the ear than the Ruger 10/22 showing a near 8dB difference. I believe Gemtech has hit a home run with the new user serviceable .22 LR units and I think they offer excellent sound reduction for anyone looking for a quality .22 unit.

As black rifles become more mainstream within the domestic shooting community, the numbers of accessories and attachments have become greater and more varied in design. Butt stocks, fore ends, pistol grips, flash hiders, and other accessories are available from any number of sources to dress up and change the features and appearance of a black rifle. In addition, uncertainty within the political and economic future has resulted in a large number of .22 caliber black rifles that are inexpensive, easy to maintain, and cheap to shoot. Enter the Gemtech G5-22, a multifunctional .22 caliber suppressor built specifically for the black rifle market.

Long known within the NFA community, Gemtech is known for making high quality products. The G5-22 is no exception. Not to be confused by its big brother, the .223 caliber G5 suppressor, the G5-22 is a miniature version of the G5 in outward appearances. Measuring 6.6 inches in length, 1.37 inches in diameter, and weighing in at a svelte seven ounces, the G5-22 produced a sound signature measuring 117 decibels when measured from a .22 caliber Thompson Center single shot rifle. First round pop was not noticeable to the ear, and was statistically insignificant when measured via sound meter. When one considers that the actions of many semiautomatic .22 caliber rifles produce 125 – 130 decibels when the bolt slams into battery, the true benefit of the G5-22 becomes apparent – the sound signature will be that of the action, and not the muzzle blast. When trying to compare what a suppressor may sound like without actually being able to fire it, this proves to be an invaluable insight into the level of sound reduction capable from this efficient little unit.

Like the G5, the G5-22 was designed with black rifles in mind. Outfitted with a miniature Gemtech bi-lock flash hider, the G5-22 mimics the feel and performance characteristics of the larger G5 without the weight or cost of the larger .223 suppressor. For those readers unfamiliar with the Gemtech bi-lock system, the system allows the suppressor to be mounted to the rifle in the same repeatable manner, each and every time the suppressor is fitted to the rifle. This is an important feature, as thread-based designs common to many suppressor designs may not provide consistent and repeatable mounting between the suppressor and the host weapon. Accuracy (or lack thereof) and inconsistency between aimed suppressed and non-suppressed fire can sometimes be traced to variables in the suppressor mounting system. The Gemtech bi-lock system removes many of the inconsistencies through the use of two offset mounting tabs that force the suppressor to be mounted to the rifle in the exact same position every time it is used. More importantly, a suppressor using the Bi-lock system may be attached or removed from the rifle in a matter of seconds. The .22 caliber bi-lock, while smaller in size than the full sized bi-lock, provides the identical features as its larger full sized .223 caliber brethren, while preserving the tactical (yet diminutive) feel and appearance of a .22 caliber black rifle. For the G5-22 to follow in the footsteps of the larger G5 suppressor, the Bi-lock mounting system was a required feature.

For safety reasons, the G5-22 will not mount to a rifle using a traditional G5 bi-lock. Designed for use with the .22 LR cartridge, the G5-22 is not capable of withstanding the forces generated by the larger and more powerful .223 cartridge. As a result, the G5-22 Bi-lock is smaller in size, thereby preventing the use of the G5-22 on a full sized .223 Bi-lock mount (preventing a potentially catastrophic end result) while also excluding the G5 from being used on the G5-22 mount thus preventing the user from adverse lead build up within the sealed and non-serviceable G5 suppressor. For users with multiple .22 LR firearms, additional bi-lock mounts may be purchased.

For those with limited knowledge of how a suppressor works and functions, questions may arise why a new suppressor is needed when the Gemtech G5 suppressor (capable of firing the more powerful .223 cartridge) is fully capable of suppressing the lowly .22 LR cartridge. In simple terms, the answer is lead vapor. Most .223 projectiles have a full metal jacket, with only the lead base of the projectile exposed. In some cases, even the base may be enclosed, limiting the amount of exposed lead to the gases generated during the firing sequence. Less lead is exposed during the firing sequence of a .223 cartridge, resulting in less lead buildup within a dedicated .223 suppressor. The same is not true of .22 LR cartridges. Typical .22 LR cartridges are composed of lead with a waxy finish. During the firing sequence, the hot gases created from the burning propellant, combined with high temperatures generated via friction between the projectile and the barrel allows a small portion of the lead projectile to vaporize. Firing quick volleys of .22 LR (whether in semiautomatic or fully automatic manner) only exacerbates the problem, as the internal temperatures increase and the lead is more easily vaporized.

While generally safe to the shooter, the lead vapor will exit the muzzle and is directed away from the shooter. From a safety standpoint, this is ideal. Nevertheless, the lead vapor will quickly condense on any cool surface encountered, including the internals of a sound suppressor. While there are .22 LR cartridges that are “jacketed,” these rounds typically feature a copper wash over the lead projectile that measures only several thousandths of an inch in thickness. While the copper wash may lessen the amount of lead vapor generated, the issue of lead vapor and leading remains.

Why is the issue of lead vapor important? Typically, large caliber suppressors are sealed and are not user-serviceable. There is no need to service a typical centerfire suppressor. Remember – lead vapor is typically not an issue for centerfire caliber cartridges. The caveat of course comes when a centerfire suppressor is used to fire .22 LR cartridges. Build up of lead vapor within the centerfire suppressor will increase weight and degrade performance over time, without the ability to clean or remove the internal lead build up. While a G5 (or any large caliber centerfire suppressor) may be used to suppress the report of a .22 caliber cartridge, the centerfire suppressor is not intended, nor recommended for long term use with .22 caliber cartridges.

Designed for the .22 LR cartridge, the G5-22 may be disassembled and is fully user serviceable for internal cleaning. In practice, the G5-22 was easily disassembled without tools. The end caps were easily unscrewed by hand and without tools to expose an inner tube used to align the internal baffles. Removing the baffles from the inner tube was easily accomplished by unscrewing the outermost baffle with a coin. Once removed, the remaining eight baffles slide out of place for cleaning and maintenance. Reassembly of the G5-22 was easy by simply reversing the steps used in disassembly. With the exception of placing the blast baffle in the proper internal position, there were no baffle alignment or sequential internal assembly steps required.

Virtually identical in use and installation to the larger G5 suppressor, the G5-22 has the added benefit of allowing law enforcement SWAT teams to train at lower cost. When installed on a .22 caliber AR-15, M16, or M4 platform, the G5-22 allows the use of inexpensive .22 caliber cartridges, while maintaining the same muscle memory required for use of the larger .223 caliber G5. In stressful situations, one must train in the same manner as the fight; the G5-22 allows the user to train at a lower cost without trying to remember how different systems are used in varying situations.

Accuracy testing showed that the suppressor did not adversely affect accuracy of the host weapon. Partly due to the consistency in mounting, and partly due to physics, users will typically find that use of a suppressor will tighten a shot group. The effect is best described by the imagining the inner workings of the suppressor. Rather than allowing gases to escape from the barrel unimpeded, suppressors typically contain and direct the gases formed during the firing sequence, allowing the bullet to exit the bore with minimal disruption. The bullet exits a suppressed bore with less external influence from the muzzle blast, resulting in greater accuracy and tighter shot groups.

The G5-22 suppressor proved to be a quality product, in line with what one might expect from Gemtech. As the first Gemtech suppressor capable of full disassembly, the design is well thought out and designed for heavy use by serious shooters. Suggested retail price is $495. The $200 NFA transfer tax will apply for the transfer of the suppressor to non-licensed individuals or entities, making the suppressor as expensive (or potentially more expensive) than the host .22 caliber firearm. Nevertheless, the ability to train on the AR-15/M16 platform using inexpensive .22 caliber ammunition will easily provide an afternoon of shooting without breaking the bank, irritating the neighbors, or worrying about an errant centerfire .223 round leaving the firing range.