18 U.S.C. § 921 — Definitions

This section defines the words used throughout the federal gun-control chapter. (a) As used in this chapter: (1) "Person" and "whoever" include an individual, a corporation, a company, an association, a firm, a partnership, a society, or a joint stock company. (2) "Interstate or foreign commerce" means commerce between a state and anywhere outside it, or within a U.S. possession (not the Canal Zone) or the District of Columbia — but not commerce that stays entirely within one state, even if it passes through another state on the way. "State" includes DC, Puerto Rico, and U.S. possessions other than the Canal Zone. (3) A "firearm" is any weapon — including a starter gun — that's built or can be readily converted to fire a projectile using an explosive; the frame or receiver of such a weapon; any firearm muffler or silencer; or any destructive device. Antique firearms don't count. (4) A "destructive device" is an explosive, incendiary, or poison-gas bomb, grenade, rocket with more than 4 ounces of propellant, missile with more than a quarter-ounce of explosive or incendiary charge, mine, or similar device; any weapon — other than a shotgun or shotgun shell the Attorney General finds is mainly for sport — that fires (or could readily be converted to fire) a projectile using an explosive or similar propellant, with a barrel over half an inch across; or a set of parts meant to be built into one of those. It does not include a device never designed as a weapon; a former weapon redesigned as a signal, pyrotechnic, line-throwing, safety, or similar device; surplus Army ordnance sold, loaned, or given away under specific statutes; or any other device the Attorney General finds isn't likely to be used as a weapon, is an antique, or is a rifle meant only for sport, recreation, or cultural use. (5) A "shotgun" is a shoulder-fired weapon built to use an explosive to fire shot or a single slug through a smooth barrel with each trigger pull. (6) A "short-barreled shotgun" is a shotgun with a barrel under 18 inches, or any shotgun-based weapon that's been modified to an overall length under 26 inches. (7) A "rifle" is a shoulder-fired weapon built to use an explosive to fire a single projectile through a grooved barrel with each trigger pull. (8) A "short-barreled rifle" is a rifle with a barrel under 16 inches, or any rifle-based weapon modified to an overall length under 26 inches. (9) An "importer" is anyone in the business of bringing firearms or ammunition into the U.S. to sell or distribute; a "licensed importer" is one licensed under this chapter. (10) A "manufacturer" is anyone in the business of making firearms or ammunition to sell or distribute; a "licensed manufacturer" is one licensed under this chapter. (11) A "dealer" is anyone in the business of selling firearms wholesale or retail, anyone in the business of repairing firearms or fitting special barrels, stocks, or triggers to them, or a pawnbroker. A "licensed dealer" is a dealer licensed under this chapter. (12) A "pawnbroker" is anyone whose business includes taking firearms as security for a loan. (13) A "collector" is anyone who acquires, keeps, or disposes of firearms as curios or relics, as the Attorney General defines by regulation; a "licensed collector" is one licensed under this chapter. (14) An "indictment" includes an indictment or a formal information in any court, charging a crime punishable by more than a year in prison. (15) A "fugitive from justice" is anyone who has fled a state to avoid prosecution, or to avoid testifying in a criminal case. (16) An "antique firearm" is a firearm — including flintlocks, matchlocks, and percussion-cap guns — made in or before 1898; a replica of one, as long as it can't use rimfire or standard centerfire ammunition, or uses ammunition no longer made in the U.S. and not easily bought through normal retail channels; or a muzzleloading rifle, shotgun, or pistol built for black powder (or a substitute) that can't fire fixed ammunition. This excludes any weapon built around a firearm frame or receiver, any firearm converted into a muzzleloader, or any muzzleloader that could easily be converted back to fire fixed ammunition by swapping its barrel, bolt, or breechblock. (17) "Ammunition" means ammunition, cartridge cases, primers, bullets, or propellant powder made for a firearm. "Armor piercing ammunition" means a handgun projectile or projectile core made entirely (ignoring trace amounts of other substances) of tungsten alloys, steel, iron, brass, bronze, beryllium copper, or depleted uranium, or a fully jacketed handgun projectile over .22 caliber whose jacket weighs more than 25% of the projectile's total weight — but it does not include shotgun shot required for hunting, frangible target-shooting projectiles, projectiles the Attorney General finds are mainly for sport, or other projectiles the Attorney General finds are meant for industrial use, including oil and gas well perforating charges. (18) "Attorney General" means the U.S. Attorney General. (19) A "published ordinance" is a published local law the Attorney General decides is relevant to enforcing this chapter, listed on a Federal Register notice updated yearly and sent to every licensee. (20) "Crime punishable by imprisonment for a term exceeding one year" doesn't include federal or state antitrust or unfair-trade-practice offenses, or a state misdemeanor punishable by two years or less. Whether something counts is decided under the law of the place it was tried, and a conviction that's been expunged, set aside, pardoned, or had civil rights restored doesn't count — unless that action specifically says the person still can't ship, transport, possess, or receive firearms. (21) "Engaged in the business" means, for each type of licensee — firearm manufacturer, ammunition manufacturer, firearm dealer, repair/fitting dealer, firearm importer, or ammunition importer — devoting time, attention, and labor to that activity as a regular trade with profit (and for the dealer and importer/manufacturer roles, livelihood) as the main goal. It excludes someone who only occasionally buys, sells, or trades to build or thin a personal collection, sells all or part of a collection, does occasional repairs, or occasionally fits barrels, stocks, or triggers as a hobby. (22) and (23) "To predominantly earn a profit" and "with the principal objective of livelihood and profit" both mean the main reason for selling or disposing of firearms is money, not something like improving a personal collection — except that proof of profit motive isn't required for someone repeatedly buying and disposing of firearms for crime or terrorism. "Terrorism" here means activity against U.S. persons committed by someone who isn't a U.S. national or permanent resident, involving violence or life-threatening acts that would be crimes in the U.S., meant to intimidate civilians, influence government policy through intimidation, or affect government conduct through assassination or kidnapping. (24) "Machinegun" has the meaning given in the National Firearms Act, 26 U.S.C. § 5845(b). (25) "Firearm silencer" and "firearm muffler" mean any device for quieting a portable firearm, including parts meant for building or fitting one. (26) A "school zone" is in or on the grounds of a public, parochial, or private school, or within 1,000 feet of those grounds. (27) A "school" provides elementary or secondary education, as state law defines it. (28) "Motor vehicle" has the meaning given in 49 U.S.C. § 13102. (29) A "semiautomatic rifle" is a repeating rifle that uses part of the energy from firing one round to eject the case and load the next, but still needs a separate trigger pull for each shot. (30) A "handgun" is a firearm with a short stock, meant to be held and fired with one hand, or a set of parts that could be assembled into one. [(31) has been repealed.] (32) An "intimate partner" is a person's spouse, former spouse, someone who shares a child with them, or someone who lives or has lived with them. (33) Except as noted below, a "misdemeanor crime of domestic violence" is a misdemeanor under federal, state, tribal, or local law that has, as a required element, using or attempting physical force, or threatening with a deadly weapon, against a current or former spouse, parent, or guardian of the victim, someone who shares a child with the victim, someone who lives or has lived with the victim as a spouse, parent, or guardian, someone in a similar role, or someone in a current or recent dating relationship with the victim. A conviction only counts if the person had a lawyer (or knowingly waived that right) and, where entitled to a jury trial, either had one or knowingly waived it — and it doesn't count if it's been expunged, set aside, pardoned, or had civil rights restored, unless that action expressly keeps the firearms ban. For a dating-relationship conviction specifically, someone with no more than one such conviction, not otherwise barred from having guns, automatically gets their rights back once 5 years have passed since their conviction or the end of any custodial sentence — as long as they haven't since been convicted of another qualifying offense. That automatic 5-year restoration does not apply to spouses, parents, guardians, co-parents, or people who've lived together in those roles — only to dating relationships. (34) A "secure gun storage or safety device" is an add-on device that stops a firearm from firing until deactivated, a built-in feature that stops anyone without access from firing it, or a safe, gun safe, case, or lock box built or usable to store a firearm, unlockable only by key, combination, or similar means. (35) "Body armor" is any product sold, or offered for sale, across state or national lines as personal protective covering against gunfire, whether worn alone or sold with another garment. (36) A "local law enforcement authority" is any state, local, or tribal government office with authority to investigate or enforce a state, local, or tribal law. (37) A "dating relationship" is an ongoing, serious romantic or intimate relationship, current or recent — judged by its length, nature, and how often and in what ways the people interacted. A casual acquaintance or ordinary business or social mixing doesn't count. (38) "Verified electronic notification," for a required message to a chief law enforcement officer under section 922(c)(2), means a digital message sent to an address the officer has voluntarily set up to receive these, that includes a way to verify both that it was received and which address it went to. (b) For this chapter, a member of the armed forces on active duty counts as a resident of the state where their permanent duty station is located.