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Cargill v. Garland: Defending ATF’s Bump Stock Ban

Case Information: Cargill v. Garland, No. 20-51016 (5th Cir. brief filed May 14, 2021)

At Issue: “Machinegun” purchases by civilians have been heavily regulated since the 1930s and effectively banned since the 1980s. In an attempt to circumvent restrictions on machine guns, manufacturers designed the bump stock–a firearm accessory that effectively converts semiautomatic rifles into fully-automatic machineguns. In 2017, a gunman used several firearms fitted with bump stocks to fire over a thousand rounds into a crowd of Las Vegas concertgoers in just minutes, killing 60 people and injuring hundreds more. In response to this incident, the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) created a new rule that classified bump stocks as “machineguns,” effectively banning them. Plaintiff Michael Cargill filed suit against ATF in the Western District of Texas, challenging the rule. The district court dismissed his complaint, and the dismissal is now on appeal before the Fifth Circuit.

Our Brief: Our brief argues that ATF’s rule should stand both because Congress’s “machinegun” ban was clearly intended to apply even to technological manipulations or advancements that convert legal weapons into machineguns, and because bump stocks have no legitimate civilian purpose. First, we describe the history of Congress’s machinegun definition, during which “machinegun” was broadened to include any “part” or “combination of parts” that could convert a weapon into a machinegun. Then we argue that bump stocks convert semiautomatic rifles into machineguns. We further argue that–because they are functionally equivalent–bump stocks are just as inappropriate for civilian use as traditional machine guns. Additionally, we argue that the court should defer to ATF’s interpretation that bump stocks are “machineguns” under Congress’s definition. Under the Supreme Court-created doctrine of Chevron deference, courts routinely defer to agency interpretations based upon the agency’s high level of technical expertise in the issues at hand and, importantly, this deference is maintained even in cases where the rules could result in criminal penalties.

Read the full text of our amicus brief here.