Posted: 12/29/2008 9:41:28 AM EDT
|
Is there anyone in the DFW area that does this work?
TIA |
|
http://www.cs.cmu.edu/afs/cs/user/wbardwel/public/nfalist/atf_letter40.txt
March 31, 1998 BATF Firearms Technology Branch Washington, DC 20226 Greetings: 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. Sincerely, DEPARTMENT OF THE TREASURY Bureau of Alcohol, Tobacco and Firearms Washington, D.C. 20226 JUN 18 1998 F:FPD:FTB:RAT 3311 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 - Mr. We trust that the foregoing has been responsive to your inquiry. If you have further questions concerning this matter, please contact us. Sincerely yours, [signed] Edward M. Owen, Jr. Chief, Firearms Technology Branch |
I see a (crush?) washer behind the FH, but how do I know where to look for a blind pin? Isn't the point that I can't see it? I cannot see any visible holes or solder, just the washer and the FH which is tapered on two sides I'd guess to grab at with a wrench 
My BBL is 16" with I guess a 1.5" FH on it (it is not a 14.5" barrel). |
|
Yeah, I guess that is what I am asking. If I don't see a pin or solder, it must be a screw on, right?
Do I really need a barrel wrench to take off the flash hider? My concern of course being I might rotate the barrel inside the upper receiver if I apply rotational pressure to the flash hider... Right?? 
|
|
Quoted:
Yeah, I guess that is what I am asking. If I don't see a pin or solder, it must be a screw on, right? Do I really need a barrel wrench to take off the flash hider? My concern of course being I might rotate the barrel inside the upper receiver if I apply rotational pressure to the flash hider... Right?? You are correct in having a concern in damaging the barrel extention pin, or upper receiver, if you twist on the barrel muzzle device, while holding the upper receiver. The proper way to install/remove muzzle devices is when clamped on the BARREL. I use an old leather chamois or belt, to protect the barrel finish, and then clamp tightly in a vise. I will clamp on the FSB if pinned, and I dont plan on twisting with massive amounts of torque. I don't recommend twisting on the muzzle device if the only thing holding the upper is the action block, as you can snap the barrel extension pin, or dapage the upper receiver, and cant the barrel. |
|
Quoted:
I already have the map gas torch. I guess I just need to find the proper solder. I don't recommend doing silver solder yourself, unless you REALLY know what you are doing. The silver solder method, if not applied 100% correctly, will allow the muzzle device to be removed with enough torque and if tested - wont pass an ATF inspection. This is why almost everyone has switched to blind pin and welding, to remove the liability. |
|
OK but a clamp around a pad on the barrel/fsb would be OK you think?
I cannot tell if my FSB is pinned or not - there's pins on the bottom but they appear to just be FSB-FSB type of pins, not actually stuck into the barrel as far as I can tell. So... barrel wrench? 
|
|
Quoted:
So... barrel wrench? Any wrench that is thin enough to get on the flats is just fine. There is nothing special about a barrel wrench to remove muzzle devices, other than some standard wrenches are too fat and wont fit on the flats without hitting and marring up the crush washer. |
|
I mean barrel wrench to hold the barrel in place while I use a regular wrench to remove the flash hider. But maybe first I will try to hold the barrel with my other hand really tight and see if I can't get the flash hider off w/out using a barrel wrench or vise.
|
|
Quoted:
I mean barrel wrench to hold the barrel in place while I use a regular wrench to remove the flash hider. But maybe first I will try to hold the barrel with my other hand really tight and see if I can't get the flash hider off w/out using a barrel wrench or vise. A Barrel wrench does not hold a barrel. A barrel wrench is used to remove barrels from receivers. You cannot use it to hold a barrel. You use a vise, with barrel vice blocks to hold a barrel. Or - you can use the method I described above, and wrap the barrel in leather and clamp tightly in a vise. You cannot hold the barrel in your hands and remove or install a muzzle device, unless your name is Lou Ferrigno and you have been irradiated with gamma rays in a freak accident. |
|
Oh ok, now I am on the same page as all of you. Thanks.
So with the belt method, do you just wrap it once or twice and vise it up? Any special side or type of belt? Also after I get it off, say I want it on for the time being –– is there any harm in leaving it on, but loose? The one I have is mostly symmetric 360' around, so I don't think it's position will matter... ??? |