NFA
(c) How registered. –– Each manufacturer shall notify the Secretary of the manufacture of a firearm in such manner as may by regulations be prescribed and such notification shall effect the registration of the firearm required by this section. Each importer, maker, and transferor of a firearm shall, prior to importing, making, or transferring a firearm, obtain authorization in such manner as required by this chapter or regulations issued thereunder to import, make, or transfer the firearm, and such authorization shall effect the registration of the firearm required by this section.
(d) Firearms registered on effective date of this act. –– A person shown as possessing a firearm by the records maintained by the Secretary pursuant to the National Firearms Act in force on the day immediately prior to the effective date of the National Firearms Act of 1968 shall be considered to have registered under this section the firearms in his possession which are disclosed by that record as being in his possession.
(e) Proof of registration. –– A person possessing a firearm registered as required by this section shall retain proof of registration which shall be made available to the Secretary upon request.
(Added Pub.L. 90-618, Title II, § 201, Oct. 22, 1968, 82 Stat. 1229, and amended Pub.L. 94-455, Title XIX, § 1906(b)(13)(A), Oct. 4, 1976, 90 Stat. 1834.)
§ 5845. Definitions
For the purpose of this chapter ––
(a) Firearm. –– The term "firearm" means (1) a shotgun having a barrel or barrels of less than 18 inches in length; (2) a weapon made from a shotgun if such weapon as modified has an overall length of less than 26 inches or a barrel or barrels of less than 18 inches in length; (3) a rifle having a barrel or barrels of less than 16 inches in length; (4) a weapon made from a rifle if such weapon as modified has an overall length of less than 26 inches or a barrel or barrels of less than 16 inches in length; (5) any other weapon, as defined in subsection (e); (6) a machinegun; (7) any silencer (as defined in section 921 of title 18, United States Code); and (8) a destructive device. The term "firearm" shall not include an antique firearm or any device (other than a machinegun or destructive device) which, although designed as a weapon, the Secretary finds by reason of the date of its manufacture, value, design, and other characteristics is primarily a collector's item and is not likely to be used as a weapon.
(g) Antique firearm. –– The term "antique firearm" means any firearm not designed or redesigned for using rim fire or conventional center fire ignition with fixed ammunition and manufactured in or before 1898 (including any matchlock, flintlock, percussion cap, or similar type of ignition system or replica thereof, whether actually manufactured before or after the year 1898) and also any firearm using fixed ammunition manufactured in or before 1898, for which ammunition is no longer manufactured in the United States and is not readily available in the ordinary channels of commercial trade.