How to permanantly attach flash hider?

http://www.atf.gov/publications/downloa ... pter-2.pdf

Per the BATFE "...Permanent methods of attachment include full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver soldering, or blind pinning with the pin head welded over..." Tack welding is not permanent enough in the ATF's opinion.

If the lower is separated from the upper (or the barrel is separated from the serial numbered part, then it's not a SBR until you are in possession of both. The safest ways are to do the paperwork before doing any cutting or welding, or, to have the barrel someplace where the receiver is NOT. I always used my brother's house as my 'out of my possession' spot.

Great link to the ATF publication - thanks! Is there any specification for what must be used as a blind pin? Can I assume 1/16" steel rod would suffice?

ChipM said:

I'm interested in switching a 16" AR carbine into a 14.5" carbine. Since my 16" carbine is essentially a 14.5" carbine with an extra 1.5" on the end of the barrel, I'm thinking that cutting the barrel is an easy way to accomplish this goal.

Click to expand...

Don't you have to re-crown the barrel at muzzle end after you cut the barrel? (Assume you already know this)

Edit to add: If you have chrome-lined barrel, doesn't it hurt the chrome finish? I'm just asking....I don't know what tool, process is used to cut a barrel....

1clearshot said:

ChipM said:

I'm interested in switching a 16" AR carbine into a 14.5" carbine. Since my 16" carbine is essentially a 14.5" carbine with an extra 1.5" on the end of the barrel, I'm thinking that cutting the barrel is an easy way to accomplish this goal.

Click to expand...

Don't you have to re-crown the barrel at muzzle end after you cut the barrel? (Assume you already know this)

Edit to add: If you have chrome-lined barrel, doesn't it hurt the chrome finish? I'm just asking....I don't know what tool, process is used to cut a barrel....

Click to expand...

Yes, you have to recrown. I don't believe it will harm a good chome lining.

Fallschirmjäger said:

Per the BATFE "...Permanent methods of attachment include ... high-temperature (1100°F) silver soldering"

Click to expand...

How is soldering done in this case? By flowing it into the threads, like on a plumbing fixture?

ChipM said:

Fallschirmjäger said:

Per the BATFE "...Permanent methods of attachment include ... high-temperature (1100°F) silver soldering"

Click to expand...

How is soldering done in this case? By flowing it into the threads, like on a plumbing fixture?

Click to expand...

yep. Just remember....no cheap stuff 8) gotta be high-temp (and the ATF is rumored to have some gorilla's in their employ). Personally, I'd think the chance of anyone getting their drawers in a twist is pretty slim, though.