Using the barrel as the registered part of an SBR...

[Bret]

P.S. silencers are similar in that you can engrave any part you want, but that doesn't change the fact that the tube is the registered part, because the ATF argues that's like the receiver of the silencer. You can have a machinist replace any part of a suppressor EXCEPT the body, just like you can replace anything but the receiver of a firearm, or the body of a registered sear. And like the case with engraving the barrel of an SBR, if you were to say engrave the thread adapter, you would have to engrave every additional thread adapter you planned on using with it, even though those aren't the body and aren't even regulated parts.

I've heard of people registering thread adapters so they can use oil filters to suppress. I'm pretty certain they're not engraving every oil filter. Rather, they just throw them away when they're done.

[Dr. Bullseye]

Yes, because Nancy Pelosi spends her evenings browsing random gun boards for gun control ideas.

Gavin Newsom and state AG Xavier Becerra sure do. Both are Nancy Bitchi's neighbors.

[okie]

I've heard of people registering thread adapters so they can use oil filters to suppress. I'm pretty certain they're not engraving every oil filter. Rather, they just throw them away when they're done.

I've often wondered exactly how those work. The only thing I can figure is the ATF gave them some kind of variance. Let's say you had a fuel filter though, where the tube was reusable and the internals were replaceable. The tube would be the registered part.