United States v. Thompson/Center Arms Co.

Background

Thompson/Center, a gun maker, sold a single-shot pistol called the Contender together with a conversion kit containing a 21-inch barrel, a shoulder stock, and a fore-end. The kit lets a buyer assemble either an unregulated long-barreled rifle or, if the shorter pistol barrel remains in place, a regulated short-barreled rifle. The Bureau of Alcohol, Tobacco and Firearms told the company the packaged unit was taxable and registrable under the National Firearms Act. The company paid one $200 tax, sought a refund, and sued after administrative delay. Lower courts were divided on whether an unassembled kit counts as "making" a firearm.

Reasoning

The Court addressed whether "making" a firearm includes packaging or producing parts that can readily be assembled into a short-barreled rifle. The statute’s definition of "make" lists manufacturing, putting together, or "otherwise producing," and different courts read those words differently. The majority concluded the statute is ambiguous on these facts and, because the NFA carries criminal penalties, applied the rule of lenity—resolving ambiguity in the company's favor. The Court therefore held that the packaged Contender and kit were not treated as a made short-barreled rifle for tax and registration purposes.

Real world impact

The decision affects manufacturers and regulators by allowing a gun maker in these facts to avoid the NFA making tax and registration. It leaves open fine-grained disputes about which part combinations count as "made" firearms, so similar products may see further litigation or regulatory guidance.

Dissents or concurrances

Justice Scalia agreed with the outcome but differed about where the statutory ambiguity lies; Justices White and Stevens dissented, arguing the kit should count as a firearm and that lenity should not apply.