Montana does not criminalize mere possession of a machine gun. It is legal to possess a machine gun in Montana:

  • For a scientific purpose;
  • If the machine gun is not usable as a weapon and is possessed as a curiosity, ornament, or keepsake; or
  • For a purpose manifestly not aggressive or offensive.1

However, possession or use of a machine gun for an offensive or aggressive purpose is a crime punishable by imprisonment in the state penitentiary for a term of not less than 10 years.2 Moreover, possession or use of a machine gun in the perpetration or attempted perpetration of a crime of violence is a crime punishable by imprisonment in the state penitentiary for a term of not less than 20 years.3

Possession or use of a machine gun is presumed to be for an offensive or aggressive purpose when the machine gun is used or possessed by a person who has been convicted of a crime of violence4 in any court of record, state or federal, in the U.S. or its territories.5

Federal law requires machine guns to be registered with the Bureau of Alcohol, Tobacco, Firearms & Explosives (ATF), and generally prohibits the transfer or possession of machine guns manufactured after May 19, 1986.6 In December 2018, ATF finalized a rule to include bump stocks within the definition of a machine gun subject to this federal law, meaning that bump stocks will be generally banned as of March 26, 2019.7

See our Machine Guns & Automatic Firearms policy summary for a comprehensive discussion of this issue.

Notes
  1. Mont. Code Ann § 45-8-307(2) and (3). ⤴︎
  2. Mont. Code Ann. § 45-8-304. ⤴︎
  3. Mont. Code Ann. § 45-8-303. ⤴︎
  4. Mont. Code Ann. § 45-8-302 defines a “crime of violence” to include any of the following offenses or an attempt to commit any of the following offenses: forcible felony, robbery, burglary, and criminal trespass. ⤴︎
  5. Mont. Code Ann. § 45-8-305. ⤴︎
  6. 18 U.S.C. § 922(o); 26 U.S.C. § 5861(d). ⤴︎
  7. Bump-Stock-Type Devices, 83 Fed. Reg. 66,514 (Dec. 26, 2018) (to be codified at 27 C.F.R. pts. 447, 478, 479). ⤴︎