And by brakes I mean a monocore that I can permanently attach to a barrel and just thread my registered tube on (similar to what SDTA now makes for SOTs only )

I ask because I've got the chance to buy some cheapish 9mm AR parts from a buddy that I'd like to use to make a second upper for my post-apocalyptic AR build....but don't want to stamp it and have zero interest in a standard 16" 9mm

Thanks guys

Bump

The ATF went after a few people, if I remember correctly. You might not find a lot of luck in finding what you are looking for.

Happy hunting.