Today the en banc U.S. Court of Appeals for the Fifth Circuit held a Bureau of Alcohol, Tobacco, and Firearms regulation extending the federal prohibition on machineguns to "bump stocks" is unlawful, as Eugene noted in a post below. In Cargill v. Garland, the judges split 13-3 on the merits, and the 13 in the majority divided on the rationale. Eight of the judges concluded the statute is unambiguous. Five additional judges concluded that, insofar as the statute is ambiguous, it should be interpreted not to cover bump stocks under the Rule of Lenity.
One aspect of the opinion, that appears to be supported by half of the judges on the en banc court, is that even were the statute ambiguous, it would not merit Chevron deference because the agency had not relied upon Chevron. Seven additional judges further concluded that ATF should not get Chevron deference because the statute imposes criminal penalties and the ATF reversed its prior interpretation of the statute. (Judge Oldham joined the first part of the court's Chevron discussion, but not the rest.)
From the en banc opinion:
