View Full Version : Expansion chamber- NFA item or no?

May 21, 2011, 10:09 PM
So here is a description of the object in question...

Let's say that a rifle with a 10.5" barrel has a 5.5" permanently affixed muzzle extension to being the total length to 16". The muzzle extension is approximately 1.25" wide and the face of it has a hole for the bullet to exit and 4 other holes placed at 90 degree intervals at the edge of the face.

With that description of a theoretical muzzle extension in mind, would it be a suppressor or a linear compensator (e.g. Noveske KX3, Levang, etc.)? Any opinions?

Nickel Plated
May 22, 2011, 05:08 PM
I believe to be a suppressor it has to be removable and reduce the shot report by 1 decibel.

BTW do integral suppressors count as NFA items? Since they are not removable. Like on an MP5SD.

Willie Lowman
May 22, 2011, 06:45 PM

May 22, 2011, 10:20 PM
Integral suppressors are NFA items as they are still suppressed.

What you are describing sounds like a muzzle brake of sorts, and as long as it is permanently attached and brings the barrel to 16" in length, it is not an NFA weapon.

David Hineline
May 23, 2011, 12:33 AM
Most likely ok, but the only way to know is to measure the sound.

If your device reduces the sound then ports or not it is a silencer.

May 23, 2011, 06:59 AM
From what I know of suppressors having 2 and rebuilding them if the muzzle of the your flash hider is closed in any form i.e. paper rubber cover etc and has no holes to the exterior and the cover is not removable or destroyed upon firing it is indeed a suppressor. Not to confuse a muzzle brake with a flash hider as flash hiders suppress the muzzle flash not sound, where as a brake suppresses recoil and usually makes the rifle louder at the shooters end do to the gas being redirected back and upward. That being said I doubt you have a suppressor of any type.

Willie Lowman
May 23, 2011, 09:24 AM
The term “Firearm Silencer” or “Firearm Muffler” means any device for silencing, muffling, or diminishing the report of a portable firearm, including any combination of parts, designed or redesigned, and intended for the use in assembling or fabricating a firearm silencer or firearm muffler, any part intended only for use in such assembly or fabrication.

If your device reduces the sound then ports or not it is a silencer.

Not always.


In this pic Tom was shooting using some kind of super long ported barrel extension called a "metro barrel" IIRC. It did reduce the report of his shotgun and the device is not controlled by the NFA.

As to not confuse the issue any more, Pullnshoot, if your muzzle device is the same inside diameter from the crown of the barrel to the muzzle of the extention, with no baffles or anything that might be mistaken for something that is designed for the "muffling or diminishing the report" there should not be any issue. In fact, here is a pic of something like what you were describing in your first post.