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

Generally, no person may carry or possess a machine gun in Massachusetts without a specially issued machine gun license. The licensing authority or the colonel of state police may issue a machine gun license to: (a) a firearm instructor certified by the municipal police training committee for the sole purpose of firearm instruction to police personnel; or (b) a bona fide collector of firearms upon application or upon application for renewal of such license.¹ Massachusetts law also prohibits the sale or transfer of a machine gun to anyone who does not hold a machine gun license.²

“Machine gun” is defined as “a firearm, loaded or unloaded, which may automatically discharge more than [one] shot by a continuous activation of the trigger, whether originally manufactured as such or modified by automatic conversion, including through the use of an automatic part or any firearm, loaded or unloaded, which has been modified by automatic conversion to alter or increase its rate of fire to mimic automatic fire; provided, however, that ‘machine gun’ shall include a submachine gun.”³

Massachusetts was the first state to enact new bump stock restrictions after the October 2017 Las Vegas shooting, in which a gunman used multiple bump fire devices to perpetrate the deadliest mass shooting attack in modern history. Massachusetts defines a “bump stock” as “any device for a weapon that increases the rate of fire achievable with such weapon by using energy from the recoil of the weapon to generate a reciprocating action that facilitates repeated activation of the trigger,”⁴ and defines a “trigger modifier” as “any modification that repeatedly activates the trigger of a firearm, including, but not limited to, trigger cranks, binary triggers and hellfire triggers.”⁵

Finally, Massachusetts prohibits any person from using any type of fully automatic machine gun or submachine gun for hunting purposes.⁶

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, 1986.⁷

1. Mass. Gen. Laws ch. 140, § 131(f).[↩]
2. Mass. Gen. Laws ch. 140, § 123.[↩]
3. Mass. Gen. Laws ch. 140, § 121.[↩]
4. Mass. Gen. Laws ch. 140, § 121.[↩]
5. Id.[↩]
6. Mass. Gen. Laws ch. 131, § 64.[↩]
7. 18 U.S.C. § 922(o); 26 U.S.C. § 5861(d).[↩]