View Full Version : Pinned flash hider/muzzle brake

December 17, 2002, 02:42 PM
Could someone please post a close-up image of a pinned and welded flash hider/brake that satisfies BATF regs? In particular for the AR-15 variants.


December 17, 2002, 07:37 PM
A flash hider like the Vortex, for example, will not fly on a post ban no matter how it is attached.

December 18, 2002, 11:09 AM
Hank - I'm straight with that. I'm just interested how the pin/weld looks on a pre-ban barrel to bring to 16".


December 18, 2002, 08:10 PM
Gotcha Noban, You are wanting to know how to attach a muzzle brake to an 11 1/2" barrel and make it be a 16" + barrel. This is a true quandry to me as the addition of the 5 1/2" long AK style brake will increase the overall length of the firearm does it really increase the length of the barrel?

December 19, 2002, 05:47 PM
Hank - It's actually a 14.5" barrel (M4 profile) with a 1.5" Phantom flash hider.

December 20, 2002, 07:43 PM
Noban, Now we have a quandry and a legal problem. :eek:

The evil flash hider is a no no on a post ban.

I don't have a picture of what you want but I might be able to explain permanently attached . It's easy, nothing is permanently attached because anything can be removed.
"Not easily removed" would be better wording in the laws but the laws must always be vague and open to interpretation by the highest ranked judges and highest paid lawyers.


December 20, 2002, 10:03 PM
1100 degree silver solder
or a blind pin that is welded over
qualifies a "permanent"

March 31, 1998

Firearms Technology Branch
Washington, DC 20226


I had some questions about permanently attaching muzzle brakes
and barrel extensions to firearms.

As you are aware, some barrels, particularly for some semi-
automatic rifles, come with muzzle threads. However, it may be
necessary, depending on the other features of the rifle, to remove
those threads, in order to keep the firearm from being considered
a "semi-automatic assault weapon". Additionally, some firearm
barrels come in lengths below 16 inches, and in order to be
installed on rifles without making the rifle subject to the
National Firearms Act, an extension may be permanently attached to
the end of the barrel, by muzzle threads, so as to make the barrel
length at least 16 inches.

I was wondering what methods of attachment to muzzle threads
are considered permanent enough so as to either extend the barrel
length, by use of an extension, or to remove the muzzle threads as
a feature of a semi-automatic rifle which might otherwise be
considered a "semiautomatic assault weapon"

In particular, I have heard that welding is acceptable. If you
can, please advise me of the method of welding, and the required
weld coverage. I have also heard that high temperature silver
solder is acceptable. If you can, please advise me as to the solder
alloy, and melting temperature that would be considered permanent.
I have also heard that some industrial adhesives are acceptable, in
particular a product called "Rocksett". I would appreciate
confirmation as to which, if any, industrial adhesives have been
found to be acceptable.

Also, if there are any other methods which I have not
mentioned above, which have also been found to be acceptable
methods of permanently installing muzzle devices onto rifles, I
would appreciate it if you could advise me of what they are.


Bureau of Alcohol, Tobacco and Firearms
Washington, D.C. 20226


Dear Mr. :

This refers to your letter of March 31, 1998, in which you ask
about permanently attaching a muzzle device to various firearms.

A muzzle device, such as a muzzle brake or barrel extension, which
is attached to a barrel by means of welding or high temperature
silver solder having a melting point of at least 1,100 degrees
Fahrenheit, is considered to be part of the barrel for purposes of
measurement. A seam weld extending at least one-half the
circumference of the barrel or four equidistant tack welds around
the circumference of the barrel are adequate for this purpose.

A firearm having a muzzle brake, cap, or barrel extension
permanently attached by those same methods to cover the threads on
a barrel, would not be considered to have a threaded muzzle.
Please note, however, that any muzzle device or barrel extension
which functions as a flash suppressor or grenade launcher would
still constitute one of the qualifying features of a semiautomatic
assault weapon as that term is defined in 18 U.S.C. section
921(a)(30(B). Industrial adhesive products are not an acceptable
method for permanently attaching a muzzle device.

- 2 -


We trust that the foregoing has been responsive to your inquiry.
If you have further questions concerning this matter, please
contact us.

Sincerely yours,


Edward M. Owen, Jr.
Chief, Firearms Technology Branch


December 23, 2002, 02:37 PM
I guess I'm not being clear.......

My barrel is a pre-ban, 14.5" 1/7 twist and I want to attach a 1.5" Phantom flash hider to bring it to 16". I fully understand the legalities of pre- and post ban requirement. I just wanted someone to post a picture of the pin and weld procedure so I can see what it looks like.

Hey, I do appreciate the responses. :)