Re: what maks an SRB a SBR?
i think you got it right, but it doesnt specify pistol conversions;
(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.
a friend who has a SOT sent me this about imported guns.
The atf now requires sbr's made after April 6, 1998 comply with the 10 parts rule as a new manufacture of a gun as a post ban sbr.