## Facts

- Thompson/Center Arms Co. manufactured the “Contender” single-shot pistol, whose barrel and grip could be removed from the receiver.
- In 1985, Thompson/Center sold a “carbine conversion kit” including a 21-inch rifle barrel, shoulder stock, and fore-end.
- Possessing the receiver with the kit allowed two relevant configurations:
  - Receiver + 21-inch barrel + stock/fore-end: a long-barreled rifle not regulated as an NFA “firearm.”
  - Receiver + 10-inch pistol barrel + shoulder stock: a “short-barreled rifle” (barrel under 16 inches) regulated as an NFA “firearm.”
- ATF advised that possession/distribution of the pistol together with the kit constituted an NFA “firearm.”
- Thompson/Center paid the NFA $200 “making” tax, sought a refund, and sued under the Tucker Act after denial.
- The Claims Court ruled for the Government; the Federal Circuit reversed; the Supreme Court affirmed the Federal Circuit’s judgment.

## Issues

1. Whether a short-barreled rifle is “made” under the National Firearms Act when a pistol is sold or possessed with a parts kit that can be assembled into either a lawful long-barreled rifle or an NFA-regulated short-barreled rifle, without proof the short-barreled rifle was assembled.
2. Whether ambiguity in the NFA’s “making” provisions must be resolved against the Government given the statute’s criminal enforcement scheme.

## Decision

- The Court affirmed the Federal Circuit and held the $200 making tax was not due on the packaged pistol and conversion kit.
- A plurality concluded the NFA is not limited to completed assembly and may reach aggregations of parts in some circumstances, but it is ambiguous when the parts set has lawful and unlawful configurations.
- Because the NFA is a tax statute backed by serious criminal penalties, the ambiguity was resolved in the taxpayer’s favor under the rule of lenity.
- A concurrence agreed that the statute’s ambiguity required judgment for Thompson/Center; a dissent would have treated the kit and pistol as sufficient for “making” an NFA firearm.

## Legal Principles

- Under the NFA’s definition of “make,” disassembled parts can constitute “making” a firearm when they can be assembled only into an NFA firearm, or when a non-NFA weapon is paired with parts whose only practical use is conversion into an NFA firearm.
- When a parts set can be assembled into either an unregulated firearm or an NFA-regulated firearm, and the statute does not clearly address that mixed-use scenario, the NFA is ambiguous as applied.
- In a tax regime enforced with criminal penalties, ambiguous statutory coverage is construed against the Government under the rule of lenity, preventing imposition of the making tax absent clear statutory authorization.

## Conclusion

The Court ruled that packaging a pistol with a conversion kit capable of lawful assembly into a long-barreled rifle did not clearly amount to “making” a short-barreled rifle under the NFA, and the resulting ambiguity—given the NFA’s criminal enforcement—required judgment for the taxpayer and a refund of the making tax.


United States v. Thompson/Center Arms Co., 504 U.S. 505 (1992)