FAQ

 

Legality? – Yes, silencers/suppressors/mufflers/moderators/cans for firearms are legal for individual ownership in 35 of the 50 United States. The favorable states are: AK, AL, AR, AZ, CO, CT, FL, GA, ID, IN, KY, LA, ME, MD, MN, MS, MT, NC, ND, NH, NV, OH, OK, OR, PA, SC, SD, IN, TX, UT, VA, WA, WI, WV,  & WY. Municipalities, Class-3 Dealers and Class-2 manufacturers, in almost any state, may also own silencers. 

 

I’ve never owned a silencer before. What should I start out with?  For starters, we usually suggest a silencer for the .22 LR rimfire round, since .22 ammo is cheap, plentiful, quiet, easily controllable and accurate. There is a learning curve involved in using a silenced firearm, and the .22 rimfire is the logical and most gratifying place to start. Most individuals select a rimfire rifle. Rifles are inherently more accurate than pistols because of the way that they are held and sighted. A few individuals are only into pistols, and a pistol is only firearm that they want to suppress.

 

What do you suggest for a host weapon? In a rifle, we suggest the imported CZ452, bolt-action military trainer – since it is both affordable and one of the finest and most accurate rifles sold in America today. We usually mount a small 1.1x7” silencer on this weapon, and suggest using subsonic rimfire ammo. Other popular semi-auto host rifles in .22 are the Ruger 10/22, Marlin’s Papoose and the Remington 597. In a pistol we suggest the Browning Buckmark, the Ruger MK II or the 22/45 target pistol. All three pistols are well made, rugged and accurate. The Beretta 21A is very small and reliable, but isn’t particularly accurate and is difficult to fit a can to properly. Walther’s P22 is light, moderately accurate, and is easier to fit a can to. Any pistol may be fitted with a removable can, or one that’s permanently mounted. If a pistol barrel is shorter than 4” special subsonic rimfire ammunition will normally not be required, since it takes from 5” to 7” of barrel to get a hi-speed round supersonic.

 

What’s the difference between removable and permanently mounted cans? Removable silencers are usually held to barrels with machine screw threads. The barrels for each weapon must be precisely threaded to match the threads on the rear of the suppressor. Threads hold the suppressor in place. A shoulder on the barrel aligns the silencing device with the bore. It is nice (but not absolutely necessary) if the hand of the threads oppose the direction of the rifling, since that will help the suppressor to stay tight. A suppressor that gets loose during firing will detract from accuracy. Both sets of threads and both shoulders must be accurately machined to ensure accuracy of the host weapon. A permanently mounted suppressor is usually tack welded, silver-brazed or bonded to the barrel of the host weapon.

 

Which is better?  A permanently mounted suppressor is more rigid, inherently more accurate and far less likely to give trouble with bullet/baffle strikes because it will never become loose. Whenever possible, we recommend a permanent mount – especially in .22 rimfire. Some law enforcement and military professionals use screw-on cans on their sniper rifles. They bond the screw-on cans to their barrels with blue Loctite, which can be loosened with a moderate amount of heat if required, yet will be sure to stay in place during handling and storage. This is done because of litigation requirements, so a can’s loosening and causing what should be an accurate shot to go wild will not affect their rifle’s scope zero.

 

What is the biggest problem with permanently mounted silencers? Moisture. Burning anything, gunpowder included, results in the generation of water. Most .22 rimfire bullets are lubricated with wax, which protects the bore. And the tiny amount of powder in a .22 LR cartridge doesn’t generate much water. Centerfire cartridges often contain more powder, which generates a lot more water. If a suppressed weapon is not pointed down during storage (and left with the action open to vent moisture out) water that condenses in the can will move into the threaded attachment and into the bore near the muzzle. It doesn’t take much water to rust things (even stainless) and a rusty bore could cause accuracy to deteriorate.

 

What is an integral silencer? About 50 years ago someone started putting tubes over barrels that were designed to look like normal barrels, but actually held very thin silencers beneath. These were called integral silencers, and their purpose was to hide the fact that the weapons were silenced from the general public and possibly, from wildlife enforcement officers. Integral silencers are specialized items and they have their own set of problems with regard to weight, maintence, reliability and accuracy. Moisture is the biggest problem. We have made a number of integral suppressors over the years. In general, integrals have been responsible for more callbacks, warranty and repair than any other type of silencer. We still make a few integrals on special request, but in general we try to discourage them.

 

What is your favorite silenced rifle setup? In .22 rimfire we like the CZ 452, short-barreled military trainer with a small, permanently mounted can and the inexpensive Tasco 3-9x40mm M scope, with a mil-dot reticle. This system is very quiet with subsonic ammo, and is often capable of 3-shot groups under ¼” at 50 yards. Individuals of small stature like a similar setup based on the CZ Youth rifle. We would have preferred to suggest an American rifle, but no company in America makes a rifle that can come close to the CZ in terms of quality, reliability and accuracy for the price. For a sniper rifle we like the standard, plain-Jane, Remington 700 VS varmint rifle in .308, or the similar Remington 700 PSS, Police Sniper Rifle, which has a slightly different synthetic stock. We usually trim the barrel back to about 22” and install a 1.6 x 9” can on the end, which removes both the sound of discharge and the muzzle flash, but not the ballistic crack caused by a supersonic bullet.

 

What is your favorite silenced pistol? Our more discerning customers have been very happy with Sound Tech’s Fat Boy can, permanently mounted on a blued, Ruger 22/45 target pistol. This setup is very quiet, operates easily, has little discernable first-round-pop, runs clean and cycles reliably. The only thing some object to in the 22/45 is that the trigger spanks the finger and holds the bolt open on the last shot – but this can be easily remedied by moving the magazine button to the other side of the magazine after disassembly, which will disable the hold-open feature.

 

What is First Round Pop? FRP is related to a louder-than-normal report. This occurs when oxygen is present within a suppressor. Since 1/5th of our atmosphere is oxygen, FRP usually occurs when the very first shot is taken. Few (if any) gunpowders retain enough chemical oxygen internally to allow total and complete combustion in the cartridge case and barrel. These hot combustion gasses often reignite after they reenter the primary chamber in a silencer on the first shot. Subsequent shots delivered in close succession are usually much quieter than the first shot in a sequence. FRP will reoccur when another shot is taken a few minutes later, as more oxygen will gradually reenter a silencer that is not sealed off from the atmosphere. FRP can be minimized with careful design, and with a very small primary expansion chamber, but it is considered a major problem within the suppressor industry. FRP is minimal with the CZ and Fat Boy .22 LR cans, but can be a problem with compact cans, extremely short pistol barrels and centerfire cans. A small primary expansion chamber in .223, .308, .50 BMG and heavier calibers will soon damage a rifle’s muzzle due to a plasma effect – causing accuracy to deteriorate because of premature melting and erosion of the barrel metal in the weapon’s bore. While some manufacturers use this technique to reduce FRP in heavy caliber cans, Sound Tech will not, because of longevity concerns.

 

What centerfire rifle calibers work best for suppression? While any rifle can be suppressed, we like compact, efficient cartridges, like .223, 6mm BR & PPC, 7mm-08, 7.62x39mm and .308. These cartridges get more work out of their moderate charges of gunpowder, and are more easily suppressed. Overbore, magnum cartridges can be effectively suppressed, but again the issue of cartridge efficiency raises its ugly head. We have had successful experiences with suppressing .223, .308, .338 Lapua Magnum and .50 BMG cartridges, and can certainly suppress any cartridge that currently exists. Very small rifle cartridges (like the .300 Whisper, for instance) are suppressible, but these are proprietary, expensive, and loaded ammunition can be hard to find. The Russian 7.62x39mm or our own .308 are larger in capacity. These are recommended instead, since they are far less expensive, more versatile and commonly available. The new Remington 6.8mm round (a virtual copy of the .280 British round developed in the UK in 1945) is now in use by some U.S. military forces. It is more peppy than the older .223 round and suppresses very well.

 

Are semiautomatic weapons as quiet as manually operated weapons? No, they are not. Self-loading weapons usually operate very rapidly, and as a result their actions open before the pressure inside the barrel has dropped completely. Particulate-laden gas issues back from the chamber area. Not only does this gas make noise, it also dumps a lot of crud into the action and magazine, which often hampers cycling. In addition, the clatter and slamming of self-loading weapons adds to the noise. Bolt-action, pump-action and single-shot weapons are much quieter and inherently cleaner than self-loading weapons because all of the internal barrel pressure has been completely vented out the front of the suppressor before the action can be opened. Those wanting the quietest report with the least amount of clatter usually choose a bolt-action rifle.

 

What barrel profiles and lengths do you prefer? We treat each caliber as a separate case – wanting a fairly thick profile and a minimum length for strength, accuracy and efficiency. In both .223 and .308 we like to see varmint or sniper weight barrels about 21+” long. This length provides good efficiency and accuracy without making the weapon longer than necessary. Shorter rifle barrels tend to be inherently more accurate than longer ones because they are inherently stiffer. They vibrate at a much higher frequency, and they vibrate much less at the muzzle during the critical moment of bullet departure. We have conducted barrel-cutting experiments to find the optimal rifle barrel lengths for the most common calibers. For instance, in .22 LR one gains little or nothing by having a barrel much longer than 8 to 10”. A good many rimfire rifle barrels are cut to 16”, just to comply with federal law regarding minimum rifle length. A 6” barrel will give us a velocity of 1,042 fps with Rem Hi Vel and 1,000 fps with Rem St. Vel. A maximum velocity of 1,180 and 1,120 fps occurs in a 14” barrel (with most rimfire chambers) after which friction reduces both velocity and accuracy. In .308, almost nothing is gained by having a barrel longer than 22”, although a few customers still insist on 26”.

 

What is ballistic crack and how does it affect suppression? Ballistic crack is a noise made whenever any projectile supersonically parts the air with a velocity at or beyond 1,100 feet per second (fps). Larger diameter projectiles make more noise, which means that .17 bullets are not as noisy as .22 bullets – both of which are quieter than .308 and .50 caliber diameter bullets. Any bullet traveling below 1,000 fps will be very quiet – making far less noise than an arrow moving through the air. Subsonic bullets are preferred for extremely quiet shooting. Although subsonic bullets don’t have very much power, they can still be very dangerous.

 

What velocity is recommended for the greatest killing power for hunting? Speed kills, and velocities beyond 3,000 fps are generally recognized as being more lethal and destructive than those velocities that are substantially slower. Pistol bullets usually make relatively small holes in elastic tissue, occasionally tearing blood vessels. Only 8% of pistol wounds are fatal. Most high-powered rifle wounds delivered to vital areas are immediately fatal. Hemorrhage and resulting blood loss are the usual mechanisms of fatality. Statistically, 90% of knife wounds are fatal to humans. Very high-velocity rifle bullets make splashes in animal tissue, which are the results of water in the tissue moving aside at velocities fast enough to tear nearby connective membranes apart. Hydraulic shock and nearby nerve damage results in almost instant incapacitation from a rifle bullet traveling beyond 3,000 fps. The rule of thumb is to use a fast bullet that is heavy enough to penetrate deeply, without necessarily going out the far side of the animal. There is very little difference in supersonic sound between a bullet at 1,100 fps and one traveling at 4,000 fps.

 

Which is best for suppression – subsonic or supersonic? Subsonic is always a lot quieter, but is lacking in power and long distance accuracy. A supersonic discharge can be suppressed, but the rapidly speeding bullet will make a lot of racket as it travels through air. In military conflicts, suppressed high-powered rifles are useful because the noise of the bullet overshadows the noise of a suppressed discharge – making it very difficult to pinpoint the exact origin of a rifle shot.

 

Are supersonic pistol cartridges worth suppressing?  Only if they are used with subsonic ammunition. For instance, a typical 9mm pistol load propels a 115 to 124-grain jacketed bullet at a very loud, supersonic, 1,300 fps; while a 147-grain subsonic loading is available that travels at a very quiet 950 fps. With the right load the 9mm cartridge suppresses very well. With the wrong load in a pistol a suppressor is simply a waste of effort. Generally speaking, a .40 caliber pistol is about 20% louder than 9mm, and .45ACP is an additional 25% beyond that – with the increase in sound being mainly due to the progressively larger size of the borehole in the suppressor. Weapons with longer barrels are usually quieter in a particular caliber than weapons with shorter barrels – either unmodified or suppressed. Ruger, Kel Tec and Berretta carbines in 9mm are a bit quieter than pistols, when using the same or a similar suppressor and 147-grain, subsonic ammunition.

 

Aren’t most .22 LR bullets supersonic? Most are, unless fired through pistol barrels shorter than 4”. This is why we recommend special .22 subsonic or target loadings in rimfire rifles. Most common rimfire ammunition is too fast in a standard rifle barrel to be effectively suppressed. The muzzle noise can be eliminated, but the supersonic crack created by the bullet remains. There is a world of difference in sound level between a suppressed, subsonic round and a supersonic round.

 

Can a revolver be suppressed? It can, but the blast noise coming from gas escaping between barrel and cylinder negates most of what a suppressor would otherwise do. Knight Mfg. suppressed quite a number of special-purpose, large frame revolvers several years back. These used O-rings to seal the barrel/cylinder gap, combined with very expensive, special ammunition. These have not been seen much, although they did work very well. The only other revolver worth suppressing is the old .30-caliber, Russian Nagant, which has a cylinder that moves forward with each shot, inserting a small amount of the mouth of each cartridge into the barrel. The mouth of the cartridge usually seals the gas at the barrel/cylinder joint, in most cases. Loaded ammunition for the Nagant is expensive, often unreliable, and very hard to find. Interestingly, the barrel/cylinder gap in most revolvers interrupts the power stroke just when a bullet is getting much of its push from a given charge of powder. It is for this reason that semi-auto and single-shot pistols are much more efficient and typically less noisy than revolvers.

 

What do you think of the Ruger 10/22 rifle? We thought enough of it to write a book on the 10/22 (available through Paladin Press) and we have suppressed thousands of them. The 10/22 is not as quiet, accurate or reliable as many bolt-action or single-shot rifles, however. Technology is always a moving target, and while it was brilliant design 45 years ago, the 10/22 is today in need of updating. The 10/22 rifle could be redesigned to be shorter, lighter, more accurate and far more reliable than it is today. The current problems relate to the magazine, cartridge feeding (the 10/22 barrel lacks a funnel or feed ramp on the rear of the barrel), trigger crispness, and the negative effect that a barrel band has on barrel vibration and accuracy. When we take older 10/22s apart we find that the barrel is often heavily worn where it contacts the barrel band, indicating the fact that rifle barrels vibrate and move a tremendous amount when being fired. And anything touching a barrel in a non-uniform way will hinder accuracy. Interestingly, Ruger’s MK II pistol was designed in 1946. It is a far more reliable design because it has a functional feed ramp and a straight-line magazine which functions even when filthy.

 

Where is firearm design heading? No one would think much of a 40-year-old computer, yet designs and improvements happen far more slowly with firearms. Today a computer, its operating system and software are outdated in 2 or 3 years, while we continue to accept firearm designs that may be hundreds of years old. The bicycle is older than the bolt-action rifle, yet design and the use of lightweight materials have made the bicycle far cheaper, easier and more comfortable to use now than it was back in the late 1800s. Bicycles don’t make much noise, while firearms do, and the noise and danger factor have prevented more widespread firearm use in many cases. The technology of suppressor design advances with moderate speed, and we will see far more silencers being used for noise abatement in the future. While a silencer on a military rifle was virtually unknown 100 years ago, few armies in today’s world would consider not having them available for at least half of their troops. As world populations increase (four million 30 years ago, to over six million today, with a projection of eight million by the year 2020) population density is also increasing. And firearm discharge noise is offensive to most, even if the weapons are being used in a controlled, safe manner. Humans have always been warlike and aggressive, and this nature is unlikely to change in the future. The U.S. appears to lead the world with the right for private citizens to own firearms for recreation and protection.

 

Firearm design has sometimes been slow to improve because old firearms continue to work, although not perfectly. Memory of the perfection of a firearm seems to improve with age, and those weapons that we had as children are revered now, even though they may not have been all that good at the time. While we agree that newer is not always better, we have seen improvements in powders, bullets and manufacturing procedures that will allow firearms to be smaller, shorter, lighter and far more accurate than they used to be in the days of flint and black powder. Magazines and feed ramps on barrels appear to be weak points that continually need attention. Barrels are typically more accurate than they ever were before. Chamber design has improved and been graded and standardized. Ammunition is better than it ever has been because of improvements in powder and bullet design. Uniform standards are now being held to SAAMI specifications, and digital controls allow more uniform charges. The use of durable plastic and aluminum allows firearms to be lighter and stronger than ever before. The company ArmaLite started as a division of Fairchild Aircraft in California, and was innovative in the engineering and analysis of component parts, using lightweight metals and reinforced plastics to build rifles and pistols that weighed less than half of what weapons of that time scaled out to. We have learned a lot about accurate barrels and more efficient cartridges. We have finally gotten over the concept of wooden stocks and firearms that need to look like what came over on the Mayflower. We will see bold, brilliant strokes in firearm design, and we will also see slow, gradual progression and refinement in finishing and technique that will allow better products to be produced at more economical prices.