Whether the definition of 'machinegun' found in 26 U.S.C. §5845(b) is clear and unambiguous, and whether bump stocks meet that definition?

QUESTIONS PRESENTED FOR REVIEW This litigation involves a 2018 Final Rule promulgated by the Bureau of Alcohol, Tobacco, Firearms and Explosives, which reversed numerous longstanding technical rulings and reinterpreted 26 U.S.C. §5845(b)’s definition of “machinegun” to criminalize the ownership of popular firearm accessories known as “bump stocks,” which the agency for decades had promised law-abiding gun owners they could purchase and possess. The courts below were unable to conclude that the agency had properly interpreted the statute, or that bump stocks are actually machineguns under the law Congress enacted. Instead, applying the framework from this Court’s decision in Chevron v. Natural Resources Defense Council, 467 U.S. 837 (1984), the lower courts merely deferred to the agency, even though the context of the Final Rule is almost exclusively criminal, and even though the agency repeatedly disclaimed entitlement to deference and entreated the courts not to apply the Chevron doctrine. The questions presented are: 1. Whether the definition of “machinegun” found in 26 U.S.C. §5845(b) is clear and unambiguous, and whether bump stocks meet that definition? 2. Whether Chevron deference should be given to agency interpretations of ambiguous criminal statutes, displacing the rule of lenity? 3. Whether courts should give deference to agencies when the government expressly waives Chevron?