Does a fixed detent pin and barrel length

[Bret]

I have Polish Mini Beryl pistol that I'm going to convert to an SBR. It has a booster & flash hider combination device at the muzzle that can't be readily removed due to detent on the font sight / gas block being fixed in place. You can't push it in to allow the device to rotate. The device does rotate back and forth on the threads a hair, but can't be removed. For the purposes of making an SBR, does the device count as a permanent part of the barrel? I need to know this in order to calculate the barrel length and overall length. I also need to know for sec922(r) compliance purposes.

[Bret]

Nobody knows?

[SteyrAUG]

While it "should" count, I think ATF requires "pinned and welded" but I have no way of knowing if that is current or how to source the actual requirement.

[Inkslinger]

Why not take an educated guess at what you barrel length is sans the muzzle device. Use that length on your form. It’s is very unlikely anyone from the ATF will ever come to check on it.

[Bret]

I could guess the barrel length, but there's also the stupid 922(r) parts count issue. If this attachment is considered part of the barrel, then there's one less part to count.

[DG23]

I have Polish Mini Beryl pistol that I'm going to convert to an SBR. It has a booster & flash hider combination device at the muzzle that can't be readily removed due to detent on the font sight / gas block being fixed in place. You can't push it in to allow the device to rotate. The device does rotate back and forth on the threads a hair, but can't be removed. For the purposes of making an SBR, does the device count as a permanent part of the barrel? I need to know this in order to calculate the barrel length and overall length. I also need to know for sec922(r) compliance purposes.

The ATF procedure for measuring barrel length is to measure from the closed bolt (or breech-face) to the furthermost end of the barrel or permanently attached muzzle device. 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. Barrels are measured by inserting a dowel rod into the barrel until the rod stops against the bolt or breech-face. The rod is then marked at the furthermost end of the barrel or permanently attached muzzle device, withdrawn from the barrel, and measured.

Does not look like their definition of 'permanent attachment' to me. Have it pinned/welded for just in case?

[Inkslinger]

I could guess the barrel length, but there's also the stupid 922(r) parts count issue. If this attachment is considered part of the barrel, then there's one less part to count.

If the pin has no signs of being welded in place, then it’s not permanent. It may be incredibly difficult to remove it, but if it can be removed by disassembling the rifle from behind, then it’s still not permanent. Just my two cents…

[SteyrAUG]

Is the roll pin directly behind it holding the detent spring and pin in place? I mean they threaded that thing ON somehow, somehow it has to come off.

[georgeib]

Is the roll pin directly behind it holding the detent spring and pin in place? I mean they threaded that thing ON somehow, somehow it has to come off.

I bet that's it. The roll pin.

[Bret]

Is the roll pin directly behind it holding the detent spring and pin in place? I mean they threaded that thing ON somehow, somehow it has to come off.

Yes, but there's no spring, just the detent.

I just had a thought. A US trigger group plus a 5.56 Promag magazine will satisfy sec922(r). I'll remove the roll pin, shorten the detent, install a detent spring and reinstall the roll pin.

Thanks everyone for your help.