604 U.S. 458
SCOTUS2025Background
- The Gun Control Act of 1968 (GCA) defines “firearm” to include: (A) any weapon (including a starter gun) that will, is designed to, or may readily be converted to expel a projectile; and (B) the frame or receiver of any such weapon.
- Advances (3D printing, polymer kits) produced “weapon parts kits” that can be assembled at home into working guns; Polymer80’s “Buy Build Shoot” kit (all parts; ~21 minutes to assemble in ATF test) is a central example.
- In 2022 ATF promulgated a rule: it would treat weapon parts kits that are “designed to or may readily be completed…to expel a projectile” as firearms (27 C.F.R. §478.11) and treat partially complete/disassembled frames or receiver kits that are “designed to or may readily be completed…to function as a frame or receiver” as frames/receivers (27 C.F.R. §478.12(c)).
- Manufacturers and others filed a pre‑enforcement APA facial challenge; the district court vacated the rule and the Fifth Circuit largely affirmed, holding §921(a)(3)(A) never reaches parts kits and §921(a)(3)(B) reaches only finished frames/receivers.
- The Supreme Court reversed: it held the ATF rule is not facially inconsistent with the GCA because at least some weapon parts kits and some partially complete frames/receivers fall within the statutory text (the Court did not decide as‑applied questions).
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether §478.11 (weapon‑parts kits) is facially invalid under §921(a)(3)(A) | Kits are not “weapons” and thus cannot meet the statutory text; statute does not intend to reach kits | Some kits (e.g., Polymer80) are artifacts whose intended function is clear and are “readily convertible” (no more conversion work than a starter gun) and thus fall within subsection (A) | Reversed: §478.11 is not facially invalid because at least some kits qualify as “weapons” that may be readily converted into firearms |
| Whether §478.12(c) (partially complete frames/receivers) is facially invalid under §921(a)(3)(B) | “Frame”/“receiver” refer only to finished components; Congress omitted “readily be converted” from (B) so (B) cannot reach unfinished parts | Artifact nouns like “frame/receiver” can include unfinished objects; statutory context (e.g., serialization in §923(i)) and ATF’s longstanding practice support regulating some partially complete items | Reversed: §478.12(c) is not facially invalid because §921(a)(3)(B) reaches at least some incomplete frames/receivers |
| Effect of textual differences between subsections (A) and (B) | Omission of “readily be converted” in (B) shows Congress did not intend to sweep unfinished frames/receivers into (B) | Subsection (B) covers the “frame or receiver of any such weapon” (cross‑referring to (A)); context and consistent statutory usage support a reading that covers some unfinished items | Court rejects plaintiffs’ textual‑difference argument; cross‑reference and context permit (B) to reach some unfinished frames/receivers |
| Whether rule of lenity or constitutional avoidance requires ruling for plaintiffs | Ambiguities should be construed in favor of regulated parties (lenity/avoidance) | Text, context, and structure resolve the questions; lenity/avoidance do not apply where statute is clear enough to answer the question presented | Court: neither lenity nor avoidance alters the outcome here; statutory text/context resolve the dispute |
Key Cases Cited
- VanDerStok v. Garland, 86 F.4th 179 (5th Cir. 2023) (Fifth Circuit held ATF rule facially invalid)
- United States v. Salerno, 481 U.S. 739 (1987) (facial‑challenge standard identifying when a law is invalid in all applications)
- United States v. Thompson/Center Arms Co., 504 U.S. 505 (1992) (applied rule of lenity in statutory ambiguity involving firearm‑part kits)
- Mullins, 446 F.3d 750 (8th Cir. 2006) (starter gun conversion can be completed by a layperson in under an hour; used to define “readily be converted”)
- Van Buren v. United States, 593 U.S. 374 (2021) (text, context, and structure govern statutory interpretation; avoid lenity if statute resolves question)
- Loper Bright Enterprises v. Raimondo, 603 U.S. 369 (2024) (contemporary and consistent agency practice can inform statutory meaning)
- Abramski v. United States, 573 U.S. 169 (2014) (describes GCA background‑check and tracing purposes)
- Bryan v. United States, 524 U.S. 184 (1998) (definition of "willfully" for criminal enforcement; relevant to mens rea concerns raised about enforcement)