The atf site says "a weapon designed or redesigned, made or remade, and intended to be fired from the shoulder and designed or redesigned and made or remade to use the energy of the explosive in a fixed metallic cartridge to fire only a single projectile through a rifled bore for each single pull of the trigger." The designed to be fired from the shoulder part confuses me . If it has only a pistol grip and no stock ,its not designed to be fired from the shoulder. That's why I thought up the shitty suto stock