term grandfathered semiautomatic assault weapon means any semiautomatic assault weapon the importation, possession, sale, or transfer of which would be unlawful under section 922(v) but for the exception under paragraph (2) of such section. (50) The term belt-fed semiautomatic firearm means any repeating firearm that— (A) utilizes a portion of the energy of a firing cartridge to extract the fired cartridge case and chamber the next round