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Sound suppressors, also known as silencers, are highly useful muzzle devices that you can use to protect your hearing and that of others.
But what should you know about them?
Why Choose a Suppressor?
Before the sound suppressor became associated with the covert and illegal — e.g., intelligence agencies and assassins — it was commonly used by private citizens for lawful purposes, such as recreational shooting and hunting. It’s thought that these devices are illegal to own, but that’s a popular myth.
Sound Suppressors 101
A sound suppressor is a tubular muzzle device that suppresses the muzzle blast and resulting report by containing the high-pressure, high-temperature expanding gases generated by the burning propellant. The suppressor uses baffles and other media to form expansion chambers, which allow the gases to slow and cool.
A sound suppressor is also popularly called a silencer. While there is an ongoing debate regarding the proper terminology, it should be noted that Hiram Percy Maxim, the designer of the first commercially successful sound suppressor, called his device the “Maxim Silencer.” The ATF, today, refers to these devices as silencers.
Regardless of what you prefer to call it, the argument that the device does not truly silence the firearm is true. All a suppressor can do is surppress or moderate the sound of a gunshot at the muzzle. There are, however, other sources of sound that a suppressor cannot reduce. These include:
In repeating firearms, this is the mechanical noise produced by the slide or bolt reciprocating on the frame or inside the receiver. Even in bolt-action rifles and pistols, the firing pin striking the primer is still audible.
If a bullet exceeds the speed of sound, it will create a miniature sonic boom, which can sound like the crack of a bullwhip. The solution to managing the sonic boom in handguns and manually operated (e.g., bolt-action) rifles is to use subsonic ammunition.
Some handgun cartridges, such as .45 ACP, are subsonic at standard pressure with 185-, 200-, and 230-grain bullets. In other calibers, such as 9mm, you will need to choose loads substituting heavier bullets (e.g., 147 grains).
In semi-automatic rifles, substituting subsonic ammunition can sometimes cause cycling irregularities due to the reduced chamber pressure.
Other Muzzle Devices
Muzzle devices are often lumped together by legislators, but they are not interchangeable. The two common types of muzzle devices are, other than sound suppressors, are:
A flash suppressor, also called a flash hider, is a cylindrical device that decreases the intensity of the muzzle flash when firing a rifle or carbine. It does this by breaking up the hot, expanding gases as they leave the muzzle.
This device helps to avoid temporary blindness and allows you to preserve your natural night vision when firing your weapon in low light or total darkness.
The principal purpose of a muzzle brake is to reduce the rearward recoil of a rifle by diverting high-pressure powder gases in the opposite direction. These devices are commonly used in hard-recoiling weapons, such as magnum and anti-materiel rifles to reduce shooter fatigue and discomfort.
A related device, the compensator, is used on pistols, submachine guns, and assault rifles to control muzzle climb during rapid semi- and fully automatic fire. However, these devices often increase the muzzle blast and report.
Why Use a Suppressor?
There has been an enormous amount of confusion and hand-wringing regarding the legal use of sound suppressors. Aren’t suppressors used by assassins, spies, and gangsters? This is the popular perception — a result of Hollywood portrayals and media punditry.
However, most of those who use sound suppressors are not criminals; they’re responsible, law-abiding citizens.
In the hands of the private citizen, a sound suppressor is, first and foremost, a safety device. Gunshots are deafeningly loud — it doesn’t take more than a few shots without hearing protection to cause permanent hearing damage.
The argument regarding hearing protection is complicated, however. Ear plugs and muffs can reduce your situational awareness. This is why hunters often omit hearing protection when stalking game.
By reducing the report at the muzzle, the suppressor reduces your likelihood of suffering permanent hearing loss. It also reduces noise pollution. Many outdoor firing ranges have been forced to close due to noise complaints. The widespread adoption of sound suppressors could be part of the solution.
What Are the Disadvantages?
A suppressor adds weight and bulk to your weapon. Additionally, due to the increased outside diameter of the suppressor tube, it may block your sight picture when using traditional iron sights. As a result, you may need to choose a set of elevated sights to align them over the suppressor tube.
You should also be mindful of your weapon’s operating cycle. Most service handguns are operated by a type of recoil, where the barrel moves linearly or tilts to unlock from the slide. The weight of a suppressor may, as a result, interfere with the cycle.
In gas-operated rifles, such as the popular AR-15, a suppressor causes the residual bore pressure to remain high for longer. This can cause the rifle to cycle more vigorously. You may need to account for this when choosing a rifle — suppressors sometimes require modifications, such as different recoil/buffer springs, buffer assemblies, and gas regulator settings.
A sound suppressor may reduce the recoil of a firearm, but this depends on the design of the weapon. In some rifles, the increased backpressure can cause the weapon to cycle more vigorously.
Does a Suppressor Reduce Muzzle Velocity?
Contrary to some film and video-game depictions, a sound suppressor has a negligible or indiscernible effect on muzzle velocity. The most likely effect that a sound suppressor will have on your firearm is to shift the point of impact. You may have to re-zero your sights to account for this.
Do Suppressors Wear Out?
As with any device that is subjected to hot, high-pressure gases, the suppressor may wear out over time. Baffles may need to be replaced. However, the notion that suppressors wear out rapidly is a throwback to designs from the 1970s that used consumable “wipes” — rubber or plastic discs that the bullet would have to penetrate.
A sound suppressor can be a highly effective piece of safety equipment or a tactical toy for range sessions. Either way, now that you know how they work and what they’re for, you can decide whether you’d like to own one.
You should determine, first, what your state and local laws are regarding suppressors before attempting to purchase one.
Sound suppressors are regulated under the National Firearms Act of 1934 and the Gun Control Act of 1968. Some states ban them altogether. So you’ll need to determine how your local laws handle these devices.
Assuming sound suppressors are legal in your state of residence, you can fill out and submit ATF Form 4 — Application for Tax Paid Transfer and Registration of a Firearm. You’ll need to pay a $200 tax and submit passport photographs and fingerprint cards. The same requirements that apply for purchasing a firearm apply — not a prohibited person, at least 21 years of age, etc.
Shooting doesn’t have to jeopardize your hearing. A suppressor can help you moderate the hazards of firearms training and recreational shooting, whether using an indoor or outdoor firing range.