The National Firearms Act, chapter 53 of the Internal Revenue Code, finds its basis in U.S. Const. Art. I, § 8, under which "The Congress shall have Power To lay and collect Taxes, Duties, Imposts and Excises…." It imposes special occupational taxes for businesses and making and transfer taxes on individual firearm transactions. It is unlawful for a person "to receive or possess a firearm which is not registered to him in the National Firearms Registration and Transfer Record," 26 U.S.C. § 5861(d), perhaps the most typical violation.
A "firearm" under the NFA includes eight categories, including short-barreled shotguns and rifles (and weapons made from shotguns and rifles under 26" overall length); "any other weapon" (small guns other than handguns); machineguns, silencers, and destructive devices. § 5845. Under H.R.1 – One Big Beautiful Bill Act of 2025, as reported by the Senate Finance Committee on June 16, 2025, § 5845 would have been amended to state: "The term 'firearm' means a machinegun or a destructive device."
As a reconciliation bill, H.R. 1 was subject to the Byrd Rule, under which an amendment is extraneous if it does not produce a change in outlays or revenues. As I argued here, the bill would have complied because it produced a change in revenues by eliminating certain firearms as taxable. The Senate parliamentarian opined otherwise. The final version as passed did not change the definition of "firearm" at all, and instead amended the making and transfer taxes on all NFA firearms except machineguns and destructive devices to $0.
