this is for personal curiosity. how are sBR's registered with the Feds? because the lower has the serial number, but the upper has the barrel? if one registers for a SBR, is that upper designated for that receiver only?
what about taking the upper and placing on an AR pistol lower (after it is registered for a SBR) or can you register pistol upper for a SBR?
now, i thought i read that the Feds say that a pistol has to come from a non registered rifle barrel, upper or the like.
any info is great.
Dupe. Link provided.