Gunco Forums banner
1 - 10 of 10 Posts

·
Happy Camper
Joined
·
7,794 Posts
Discussion Starter · #1 ·
FOUND IT:

http://www.falfiles.com/forums/show...ht=blind+muzzle

quote:

DEPARTMENT OF THE TREASURY
BUREAU OF ALCOHOL, TOBACCO AND FIREARMS
WASHINGTON, DC 20226

FEB 2 2000

903050:EMO
3311

Mr. XXXX XXXXXX
XXXXXX XXXXXX
XXXX XX XXX
XXXXXXXXXX, XXXXXXXX XXXXX

Dear Mr. XXXXXX

This is in reply to your letter dated December 28,
1999, in which you ask about permanently affixing
muzzle brakes your firm produces to barrel muzzles
of "post ban" AR15 type rifles.

You indicated that the barrel muzzle will be threaded
to accept the muzzle brake. The brake will be screwed
to the barrel muzzle and a 3/32 inch hole .030 - .050
inches in dpeth will be drilled into the barrel wall
using an existing set screw location in the brake as a
pilot hole. A 6X32 TPI set screw will be installed
through the pilot hole and into the described blind
hole in the barrel. The set screw hole will be welded
over after installation of the screw to permanently
affix the brake to the barrel. Excess wild will be
removed and the muzzle brake refinished to conceal the
location of the weld.

The above described procedure has previously been
approved for use in permanently affixing muzzle
attachments to rifle barrels. An AR15 type rifle
barrel having a muzzle brake affixed as described
above would no longer be considered to have a threaded
muzzle provided that deep penetrating steel fusion
welding is used.

/quote

"...printed it out from the Wilson Combat website back in April 2000.
The source is the ATF, in response to a letter about the attachment method from Wilson Combat.
The author is Edward M. Owens (hence the EMO at the top) the now-retired head of ATF Firearms Tech Branch."
 

·
Registered
Joined
·
13 Posts
Instead of welding could you insert a screw and then grind the head off it flat with the muzzle break?
I am a little unclear how this is done.
Is it #1 like a regular set screw or #2 like how the barrel is set in the trunnion?
 

Attachments

·
Registered
Joined
·
83 Posts
I'm curious, now that we are in a NO-BAN situation, why is this important?

Is this info relevant for AMD 65 builds? Could we use this method to attach barrel extensions and brakes to make the barrel length legal?
 

·
Registered
Joined
·
704 Posts
Yes you can.
 

·
Registered
Joined
·
83 Posts
This is good. It sounds like we may be able to attach an extension without ruining the original barrel. The only permanent change would be the set screw dimple in the threads.
 

·
Registered
Joined
·
1,856 Posts
JW762x39 said:
Instead of welding could you insert a screw and then grind the head off it flat with the muzzle break?
I am a little unclear how this is done.
Is it #1 like a regular set screw or #2 like how the barrel is set in the trunnion?
I believe #1 is the prefered method. Don't forget that the hole must be welded over (then contoured to the part).
 

·
Registered
Joined
·
66 Posts
bbowling said:
I'm curious, now that we are in a NO-BAN situation, why is this important?

Is this info relevant for AMD 65 builds? Could we use this method to attach barrel extensions and brakes to make the barrel length legal?
It is important for barrels that don't meet the 16inch minimum such as the AMD 65 and M4 clones. You can either blind pin/ blind screw/weld the barrel extension, silver solder it or weld it.
As long as the barrel is longer than 16 inches then you can have evil exposed threads and a removable muzzle device.
 

·
Registered
Joined
·
13 Posts
Toten Kopf said:
I believe #1 is the prefered method. Don't forget that the hole must be welded over (then contoured to the part).
But does it have to be welded if you eliminate the possibility of unscrewing
the inserted screw?
 

·
Master Endmill Breaker
Joined
·
1,367 Posts
JW762x39 said:
But does it have to be welded if you eliminate the possibility of unscrewing the inserted screw?
Yes. Even a screw that is ground off must be welded.
 
1 - 10 of 10 Posts
Top