II 119th CONGRESS 1st Session S. 1374 IN THE SENATE OF THE UNITED STATES April 9, 2025 Mr. Heinrich (for himself, Ms. Collins , Ms. Cortez Masto , Ms. Rosen , Mr. Fetterman , Mr. Coons , Ms. Klobuchar , Mr. Kaine , Mr. Reed , Mr. Whitehouse , Mr. Blumenthal , Mr. Durbin , Mrs. Shaheen , Mr. Padilla , Ms. Smith , Mr. King , Mr. Kelly , Mr. Bennet , Ms. Duckworth , Mr. Markey , Mr. Van Hollen , Mr. Sanders , Mrs. Murray , Mr. Wyden , Mr. Booker , Ms. Hirono , Mr. Welch , and Mr. Schiff ) introduced the following bill; which was read twice and referred to the Committee on the Judiciary A BILL To amend title 18, United States Code, to prohibit machinegun conversion devices and illegal modifications of semiautomatic firearms, and for other purposes.

1. Short title This Act may be cited as the Banning Unlawful Machinegun Parts Act or the BUMP Act . 2. Prohibition (a) In general Chapter 44 of title 18, United States Code, is amended— (1) in section 921(a), by inserting after paragraph (30) the following: (31) The term semiautomatic firearm means any firearm that— (A) upon initiating the firing sequence, fires the first chambered cartridge and uses a portion of the energy of the firing cartridge to— (i) extract the expended cartridge case; (ii) chamber the next round; and (iii) prepare the firing mechanism to fire again; (B) requires a separate pull, release, push, or initiation of the trigger to fire each cartridge; and (C) is not a machinegun. ; (2) in section 922, by inserting after subsection (u) the following: (v) (1) Except as provided in paragraphs (3) and (4), on and after the date that is 120 days after the date of enactment of this subsection, it shall be unlawful for any person to import, sell, manufacture, transfer, receive, or possess, in or affecting interstate or foreign commerce— (A) any manual, power-driven, or electronic device primarily designed, or redesigned, so that when the device is attached to a semiautomatic firearm the device— (i) materially increases the rate of fire of the firearm; or (ii) approximates the action or rate of fire of a machinegun; (B) any device, part, or combination of parts, that is designed or functions to materially increase the rate of fire of a firearm, by eliminating the need for the operator of the firearm to make a separate movement for each individual function of the trigger; or (C) a semiautomatic firearm that has been modified in any way that— (i) materially increases the rate of fire of the firearm; or (ii) approximates the action or rate of fire of a machinegun. (2) Except as provided in paragraph (3), not later than 120 days after the date of enactment of this subsection, any person who lawfully owns or possesses a semiautomatic firearm that was modified as described in paragraph (1)(C) before such date of enactment shall register the semiautomatic firearm in accordance with section 5841 of the Internal Revenue Code of 1986. (3) This subsection does not apply with respect to the importation for, manufacture for, sale to, transfer to, or possession by or under the authority of, the United States or any department or agency thereof or a State or Tribe, or a department, agency, or political subdivision thereof. (4) Paragraph (1) shall not apply to any lawful transfer or possession of a semiautomatic firearm described in paragraph (1)(C) that— (A) was lawfully modified and possessed before the date of enactment of this subsection; and (B) is registered in accordance with paragraph (2). ; and (3) in section 924(a)(2), by striking , or (o) and inserting (o), or (v) . (b) Amendment to the National Firearms Act Section 5845(a) of the Internal Revenue Code of 1986 is amended by striking and (8) a destructive device and inserting (8) a destructive device; and (9) a semiautomatic firearm, as defined in section 921 of title 18, United States Code, that is modified as described in section 922(v)(1)(C) of such title .