handguns and silencers

A few questions for you folks that know firearms.
In movies and on TV, silencers are always installed on the end of a handgun by screwing it in, sort of like putting a lightbulb in a socket. However, I’ve never seen a handgun with threads to accept a silencer. So

  1. Are guns made to accept silencers after the fact, or can any gun accept a silencer?

  2. How, if you screw a silencer into the muzzle of a handgun, is the bullet able to fly out of the barrel when the diameter of the barrel would shrink slightly with the insertion of the silencer?

  3. Are silencers legal anywhere? If so, where?

  4. If not, I assume silencers are a black market item. Who can manufacture something like this that requires some tool and die expertise, quality control it, and get it to its potential customers without raising any eyebrows? (I realize that the answer to this question might be conjecture)

Until someone more experienced and knowledgeable arrives:

  1. Dunno

  2. The silencer is screwed onto threads outside of the barrel. No constriction occurs.

  3. Generally most places (U.S.) but there are a *lot/I] of hoops and paperwork (and fees).

  4. Commercially available but see #3.

Also until somebody with more knowledge comes along;

They can either be built with one or have one attached, as such;


This vid shows a fella attaching a silencer to an airsoft gun, using the Hollywood-style ‘screw’ method. As you can see, the gun barrel doesn’t have threads, it’s a separate plug attachment.

Wiki has a cross-section of a pistol silencer - the silencer in this case doesn’t protrude into the barrel, but is fitted over the muzzle. There are, however, a large variety of silencer designs (and firearms they are fitted to).

In the U.S. they are heavily regulated under the National Firearms Act of 1934. In other countries, such as Finland, Norway and New Zealand, they are legal and unregulated. Wiki has an overview of the legal status of silencers worldwide.

  1. Some guns come with threaded barrels but most don’t. Most gun manufacturers sell replacement barrels pre-threaded for suppressors. Otherwise you can thread it yourself if you have access to a metal lathe. Many guns that depend on gas to chamber to the next round need to bedified or use modified or special ammo because the suppressor effects the expansion of gas so much.

2)If it threads into the barrel the bore is made wider prior to threading so there is no interference. The bore of the supressor is usually a few thousandths bigger than the barrel to avoid the bullet possibly striking it. Some supressors screw to the outside of an extended barrel you buy from the gun manufacturer.

  1. Suppressors are legal in the US. In thirty plus states anyway. You need a special permit to get one though.

  2. You can make them at home but it’s probably not worth the effort since you can buy them online legally and they will be of much higher quality.

How well do they work? I assume the sort of chuff chuff one hears in movies is an exaggeration.


Depends on whether the ammunition is subsonic or not. From another thread, on homemade silencers;

Here’s a guy testing a silenced assault rifle with various forms of sub-sonic ammunition. Here’s a guy with a number of silenced firearms. And just for the lulz, here’s a guy who silenced a Nagant revolver. The ‘fwip fwip’ sound is a Hollywood invention, it seems. Here’s a website that appears to test a number of professionally made silencers.

With subsonic ammo they can be fairly quiet. Subsonic ammo is limiting in range though. With supersonic rifle ammo the idea is less making it super quiet than it is making it not deafening in tight quarters and reducing the enemies ability to acquire your position easily.

Thanks to you both.


Minor nitpick: You don’t need a permit. You just need to pay a special tax and have your paperwork (which often includes a photograph, fingerprints, and LEO sign-off) approved by the ATF. But there’s no actual permit.

On many semi-automatic pistols, threading the stock barrel is difficult if not impossible because there is minimal if any protrusion of the barrel from the slide.

In such a case either a longer barrel would have to be created, or an extension would have to be added to the barrel, typically via brazing.

Threading a barrel internally isn’t really practical, as there is not enough wall thickness beyond the bore to support two threaded parts (the barrel and the silencer both need some meat for strength.

My Ruger 10/22 came with the muzzle already threaded for a silencer (the local store does them all like that). As I have no use for one I made a brass sleeve to cover the thread.

Revolvers are difficult to silence effectively as the sound leaks through the cylinder/barrel gap. Historically, Hollywood has tended to use revolvers a lot as there is no trouble to make them work with blank cartridges on the set. Autos require considerable modification to make the mechanism function with blanks but today this work is frequently done. The ‘silencer’ may well in fact contain the bore restrictor which chokes the gases of combustion enough to function the action (the noise will be dubbed on in post-production anyway).

The Parker-Hale Sound Moderator http://www.parker-hale.co.uk/mod.htm is one which has, in the past, been quite widely sold here for pest controllers. If it was for an air-gun you could buy one without controls (cartridge firearm ones do require to be registered but it’s no big deal).

A silencer is considered to be a class 3 device which has to be registered individually on an annual basis. I believe the annual fee is $250. That’s per device, not per owner for however many you have.

Small selection online here.

They fall under the same classification as fully automatic weapons, drum fed shotguns, and other fun toys.

Some come with a threaded barrel. Most do not.

The threads are on the outside of the barrel so there is no constriction.

Not everywhere, but they are legal in most states.

Nope. They are manufactured in a perfectly legal fashion, and barring local restrictions are perfectly legal to own. Do a search at Gunbroker.com and you’ll find anything your heart desires.

Nope. The tax is $200 and it is only paid once for the initial transfer.

Thank you all for the great answers!

A follow-up.

What is the legal justification for this product? I’m not anti-gun by any means, but it would seem the most obvious reason to need/use a silencer is for criminal activity (perhaps to kill another). I understand that if you want to kill someone with a gun, the gun, not the silencer, is the tool that kills. But the silencer would certainly help reduce the chances of someone overhearing the gun going off.

Is there any other reason one might justify using a silencer? Aside from not wanting to disturb your neighbors while you plunk moles or squirrels in your back yard, why would you use one? Or is it as simple as that (noise reduction)?

It’s as simple as that, really. Prolonged shooting (for whatever reason, although the problem is explained in regard to shooting for sport here) can have negative effects on the ears. Hence why people wear ear protection at shooting ranges and what have you. Note that even with silencers, weapons firing supersonic ammunition are still very audible (as you can also hear in the linked vids):


See also:

Buying a silencer requires one to fill out a BATFE Form 4, get fingerprinted and photographed, and have the Chief Law Enforcement Officer within the locality sign off on the purchase.

That must be sent in to the BATFE with the $200 tax, whereupon they issue the tax stamp, usually 2-3 months later after a thorough background check. Then you have to get it transferred through a person who deals with those items, who charges a much higher transfer fee. There is a substantial investment made in the item before you ever take possession. Incidentally, none of this is guaranteed. The CLEO is not under any legal obligation to sign you off, and the BATFE does not have to approve you, although they keep the money even if you are rejected.

Then, after you are approved, you have to have the paperwork with you at all times when you use it. If you do not you can (and will) be charged with a firearms crime.

All of this mitigates the use of silencers in the commission of a crime. People will not willingly expose themselves to these terms and conditions and identify themselves to the government if they intend to commit a crime. A silencer (technically a suppressor, by the way) has not been used in any crimes that I am aware of. The penalty is very high for any sort of violation and will be tacked on above and beyond any other penalty for the crime committed, and since the BATFE knows you have a silencer, you will almost certainly be caught if you commit a crime with it.

The purpose is to reduce the report of the weapon, typically a .22 Long Rifle but sometimes a larger caliber. In some areas where people have a large swath of land suitable for firearms use but have neighbors that object to the sounds of gunfire a silencer is quite useful. And some people just collect them for the cool factor because they can.

There have been occasions when I’ve had to deal with a pack of feral dogs when a suppressor would have been useful. One of the joys of living in the country is that everyone seems to think it’s a great idea to dump out an unwanted dog that has had no experience living on its own. 5 or 6 get together in a pack and start being a danger to livestock, pets, and even residents. It’s usually only possible to shoot two of them before the rest scatter and run. With a suppressor on my rifle I could probably take out most, if not all of them.