August 9, 2022 – A three judge panel of the U.S. Court of Appeals for the D.C. Circuit issued a decision unanimously affirming the trial court’s decision that the Bureau of Alcohol, Tobacco, Firearms and Explosives (“ATF”) properly classified bump stocks as machine guns.   Although the ATF had previously concluded that bump stocks are not machine guns, after a 2017 shooting at a music festival in Las Vegas, the ATF issued a rule reclassifying bump stocks as machine guns. 
Plaintiffs challenged the rule, arguing ATF lacked authority to issue the subject rule and impermissibly expanded the legislative definition of machine guns without action by Congress. Plaintiffs specifically noted that the ATF had advised on at least ten prior occasions that a bump stock is not a machine gun.
The court concluded that it did not have to address the issue of whether the ATF’s determination that bump stocks are machine guns was entitled to deference, because its interpretation of bump stocks as falling within the statutory definition of a machine gun was the best interpretation.  A machine gun is defined, in relevant part, as any “weapon which shoots . . . automatically more than one shot, without manual reloading, by a single function of the trigger.”  Included within the definition of a machine gun is “any part designed and intended solely and exclusively, or combination of parts designed and intended, for use in converting a weapon into a machinegun . . . .”
The court agreed with the ATF that the term “single function of the trigger” equates to the “shooter’s volitional action that initiates an automatic firing sequence.”  Because a semi-automatic firearm equipped with a bump stock will continue to fire automatically once the shooter initiates the firing sequence, the court concluded that the ATF properly classified bump stocks as machine guns.
The court explained that “employing the traditional tools of statutory interpretation, we find that the disputed rule is consistent with the best interpretation of ‘machine gun’ under the governing statutes” and that “a bump stock is a self-regulating mechanism that allows a shooter to shoot more than one shot through a single pull of the trigger.” The U.S. Courts of Appeal for the Fifth, Sixth, and Tenth Circuits have all also held that the ATF properly classified bump stocks as machine guns.
Renzulli Law Firm will continue to monitor this case and other challenges to federal firearms regulations.  If you have any questions about this case, the ATF’s ban on bump stocks, or federal firearms laws, please contact John F. Renzulli or Christopher Renzulli.