[1][2] However, as with all private-letter rulings, these determinations on the U.S. legality of binary triggers are limited to the specific facts about the devices being examined.
Any such legal opinion may be modified or revoked at any subsequent time by the Bureau of Alcohol, Tobacco, Firearms and Explosives.
Binary triggers became popular in the United States after the 2017 Las Vegas shooting as trigger cranks and bump stocks, devices similarly used to increase firing rate, had largely disappeared from online sellers due to fear of legal repercussions.
[4] However, in wake of the shooting, binary triggers also received scrutiny by media outlets.
[5] On January 1, 2025, a law that bans binary triggers went into effect in Minnesota[6] following their use in the 2024 Burnsville shooting.