How do suppressors work? Read on to find out more about the mechanics, physics, and makeup of firearm silencers plus regulation for carriers!
How Do Suppressors Work? | The Science Behind Silencers
Suppressors are covered by the National Firearms Act (NFA). This document defines what a silencer or suppressor is. If you have never read any kind of federal rule such as the NFA, it will give you a headache, so I’ll give you the gist.
Section 2.1.7 of the NFA defines a silencer as follows:
A firearm silencer and a firearm muffler are defined as any device for silencing, muffling, or diminishing the report of a portable firearm. Firearm silencers are generally composed of an outer tube, internal baffles, a front end cap, and a rear end cap.
The document goes on to say, “The definition of a silencer also includes any combination of parts, designed or redesigned, and intended for use in assembling or fabricating a firearm silencer or firearm muffler.”
This quite simply means that any piece or part that can be used to make or repair a suppressor is a suppressor and is controlled just like a fully assembled suppressor.
At the federal level, anyone can own a suppressor if they meet the basic rules, fill out the forms get the local Police Chief or Sheriff to sign off on it and pay the $200 tax. However, many states do not allow an individual to own a suppressor (see below).
The Basic (Federal) Rules for Suppressors and Silencers
- Must be 21 years old when purchasing from a dealer
- Typically, if you can buy a handgun, you can buy a silencer
- Must not have been convicted of a felony or pleaded guilty to domestic violence charge(s)
- Must be a United States Citizen
The following states allow civilian ownership of silencers:
- New Hampshire
- New Mexico
- North Carolina
- South Carolina
- South Dakota
- Washington (allows possession but not use)
If your state isn’t listed here, you will not be able to own a silencer.
Once a suppressor is transferred to you, you can’t loan it to a friend, and you can’t take it out of the state you live in unless you do the correct paperwork.
How Suppressors Really Work
To put it simply, a suppressor is a muffler for your firearm and it works just like the muffler on your car. It redirects and slows down the high-pressure gas from firing the weapon. It can be made out of just about anything, but it is usually a tube attached the barrel of a firearm. This tube would usually have holes in it to redirect the gas to a series of baffles or chambers which bleed off gases into the chambers and slow it down, thus reducing the sound of the shot.
The tube and baffles would be in an enclosure or “can”, which can be made out of high-tech materials like carbon fiber and titanium or as low tech as a 2-liter soda bottle with some water in it. A suppressor can be purchased from a Class III FFL for a couple of hundred dollars to several thousands of dollars, plus the $200 tax stamp.
As long as you follow the rules you could make your own. But remember once you do that you open yourself up to inspections by the Bureau of Alcohol, Tobacco, Firearms, and Explosives. And as mentioned above, any part of a suppressor is a suppressor.
What to Expect in Suppressors
One thing to keep in mind is that a suppressor does not make firing a weapon completely silent, but it will reduce the sound’s signature to the point where you don’t need earplugs and muffs. Hearing protection is still required for prolonged exposure.
As an example, a .22LR makes about 160 dB. With a good suppressor, you might be able to reduce that to about 120 dB. Besides the sound made by the explosion and expanding gas, the bullet itself will make noise as it goes supersonic. Using sub-sonic ammunition will fix this problem, but keep in mind that in a semi-automatic, a sub-sonic round may not have enough energy to cycle the action.
Over the years, suppressors have been used in movies and television by good guys and bad guys and attached to just about anything you can think of, and just about any type of firearm that uses a closed bolt can be suppressed.
My definition of a closed bolt is a firearm where the firing chamber is sealed. This can be a semi-auto, single shot, bolt action, handgun, rifle, shotgun or machine gun.
Contrary to what they show in older television shows and movies, a revolver cannot be fully suppressed. The gap between the cylinder and the barrel allows expanding gas to escape which defeats the purpose of a suppressor.
The Mosin Nagant M1895 Revolver
There is, however, one revolver that can be suppressed. That is the Mosin Nagant M1895 revolver chambered in 7.62×38mmR, and featuring a very unusual “gas-seal” system, where the cylinder moved forward when the gun was cocked, sealing the gap between the cylinder and the barrel. Among other things, this allows the weapon to be suppressed. My research shows that this is the only mass-produced revolver that can be suppressed.
Suppressors have long been seen as a tool used by assassins and spies with a license to kill, but changing laws around the county are making the use of a suppressor for hunting and target shooting more commonplace. As their use becomes more accepted, the number of manufactures and the quality goes up while the price goes down.
Check out this video from SilencerCo on how a silencer is made, specifically the SILENCERCO SAKER 5.56:
How do suppressors work? It’s probably the first question a lot of gun newbies ask. This is likely because suppressors or silencers have long been the stuff of movies and TV. Because of that, there are a lot of misconceptions about what a suppressor is, the legalities of owning one, and the science behind them. This article should clear all that up and we hope it gave you a solid background in suppressor tech and application.
Disclaimer: The contents of this article are for informational purposes only. Please read our full disclaimer here.
Editor’s Note: This post was originally published on March 23, 2015, and has been updated for quality and relevancy.