Monkeyman:
The AWB (codified at 19 USC 921 et seq) distingishes between flash hiders and muzzlebrakes, as well as threaded barrels. Under the soon-to-expire AWB, the barrels could not be threaded and remain post-ban. Solution: permanently attach a non-flash suppressor/non-granade launcher to cover the threads.
The National Firearms Act (NFA) (codified at
26 USC ch. 53) requires rifles to have both an overall length greater than 26" AND barrels greater than 16", OR be registered as Short Barreled Rifles (SBR's). The barrel must not be readily convertable to a sub-16 inch length, hence the requirement that the attachments to sub-16" barrels be "fixed" or permanent. Violation of the NFA is a 10 year/$10,000 penalty -- serious stuff.
Don't confuse the requirements of completely different laws. BTW the NFA is part of [
legislation] from I beleive the 1930's, and it's not going anywhere any time soon.
This reply goes equally for your response in this thread:
11.5 inch barrel Cheers, Otto
Edited to correct the penalty, above.