Pin and weld materials?

**Franky4Fingers** · April 17th, 2012, 05:35 PM

Does the ATF actually have a list of materials or processes that it finds acceptable? Or does it just simply say to permanently fix the muzzle device, like a flash hider?

I ask because, I'm wondering if you could just use JB Weld to fix the pin? Its permanent. I've seen that stuff hold on hot greasy engines, and gets hard as metal when cured. If you filled in the pin hole, sanded it down, and hit it with some BBQ paint. I can't see how you would know the difference if it were soldered, or welded.

I actually fear welding the barrel because of ruining the finish, plus, possibly warping the metal. Being a professional welder, I know all too well how that works. Same goes for fusion or brazing. Even soldering needs to be heated with a torch.

**brian** · April 17th, 2012, 08:00 PM

silver soldering it will not harm the barrel. the finish yes, but that is price to pay for permantly attaching something.
i have a cutts comp on a thompson silver soldered on, and you would never know it, other than the tiny bit of silver that can be seen.

**Franky4Fingers** · April 17th, 2012, 08:52 PM

I've doing some research I suppose it has something to do with solder being 1100 degrees and JB weld is 600. Plus it doesn't absorb impacts well.

**knight0334** · April 18th, 2012, 11:37 AM

If you're trying to avoid having a SBR because of a short barrel - it must be:

1. full fusion welded with gas or electric seam welding, or
2. blind pinned and the pin head welded over, or
3. silver soldered

Loctite, and JB Weld will not make the grade.

JB Weld melts around 600'F and doesn't take impacts or vibration well. Its only a matter of time before a JB Weld joint/fusion fails.

Loctite can be heated up as well and loosened.

See ATF NFA Handbook pages 17 and 18 of 200 PDF file - http://www.atf.gov/publications/down...f-p-5320-8.pdf

If the gun is registered as a NFA device - then it really doesn't matter how you attach it.