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, 1986.¹ 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, 2019.²

Hawaii prohibits the manufacture, possession, sale, barter, trade, gift, transfer, or acquisition of automatic firearms.³

In 2018, Hawaii prohibited the manufacture, sale, or possession of bump stocks which are a type of firearm accessory that can significantly increase its rate of fire to function similarly to a machine gun. In October, 2017, a shooter used multiple bump stock devices in an attack on concert-goers in Las Vegas to perpetrate the deadliest mass shooting attack in modern history. Hawaii defines a “bump stock” as “a butt stock designed to be attached to a semiautomatic firearm and designed… to increase the rate of fire… by using energy from the recoil of the firearm to generate a reciprocating action that facilitates repeated activation of the trigger.”⁴

Hawaii also prohibits two additional types of trigger activators:⁵

(A) “Trigger cranks,” defined as “any device to be attached to a semiautomatic firearm that repeatedly activates the trigger of the firearm through the use of a lever or other part that is turned in a circular motion…” and

(B) “Multiburst trigger activators,” which are

(1) Devices that simulate automatic gunfire by allowing standard function of a semiautomatic firearm with a static positioned trigger finger or a device that fires multiple shots with the pull and release of the trigger; or

(2) Manual or power-driven trigger activating devices constructed and designed so that when attached to a semiautomatic firearm they simulate automatic gunfire.

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

1. 18 U.S.C. § 922(o); 26 U.S.C. § 5861(d).[↩]
2. Bump-Stock-Type Devices, 83 Fed. Reg. 66,514 (Dec. 26, 2018) (codified at 27 C.F.R. pts. 447, 478, 479).[↩]
3. HRS §134-8(a).[↩]
4. HRS §134-8.5(b).[↩]
5. Id.[↩]