HardHatMan
FBHO
Been a while since I read the wording of the law, but even if it weren't attached(which it is), I don't think that is their wording. I believe the wording is something like 'designed to be fired from the shoulder.' Trying this on an AR pistol not registered as a SBR is sure to be in violation, in the ATF's eyes.
Hmmm, I just looked up the US code defining an SBR:
(8) The term “short-barreled rifle” means a rifle having one or more barrels less than sixteen inches in length and any weapon made from a rifle (whether by alteration, modification, or otherwise) if such weapon, as modified, has an overall length of less than twenty-six inches.
http://www.law.cornell.edu/uscode/s...tml/uscode18/usc_sec_18_00000921----000-.html
If it starts life as a pistol, then it would never of have been considered a rifle, correct?