Whether the Gun Control Act of 1968 (GCA) authorizes the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to regulate "weapon parts kits" as firearms. Specifically, the Court must determine if such kits and partially complete frames or receivers fall within the statutory definition of a "firearm" under 18 U.S.C. § 921(a)(3). The case asks whether ATF's 2022 rule interpreting these terms is facially inconsistent with the GCA.

• Weapon parts kits and unfinished frames are designed for ready conversion into functional firearms and thus fit the statutory definition of a "firearm."
• These "ghost guns" create a significant law enforcement crisis because they are untraceable, as evidenced by the jump from 1,600 to over 19,000 ghost guns submitted for tracing between 2017 and 2021.
• The GCA's broad definition of "firearm" is intended to prevent criminals from evading federal licensing, background checks, and serialization requirements.

• The GCA cannot be read to reach weapon parts kits or unfinished frames because they are not yet functional weapons.
• Unlike other sections of the Act that explicitly cover "combinations of parts," § 921(a)(3) does not use such language, implying it only reaches finished items.
• Regulating these components could lead to unintended consequences under the National Firearms Act (NFA), potentially allowing the government to classify popular semiautomatic AR-15 receivers as machineguns.

• The ATF's rule is not facially invalid because at least some weapon parts kits and unfinished frames satisfy the GCA's definitions.
• Under 18 U.S.C. § 921(a)(3)(A), "weapon" is an "artifact noun," meaning it describes objects based on their intended function rather than a finished state; thus, disassembled rifles or kits with clear intended functions can be "weapons."
• The Court noted that the statute explicitly includes "starter guns," which often require conversion to fire live ammunition in less than an hour (*United States v. Mullins*), proving Congress intended to cover some unfinished instruments of combat.
• A kit is "readily convertible" if it requires no more time, effort, or expertise to complete than a starter gun; therefore, kits like Polymer80's "Buy Build Shoot," which can be assembled in roughly 20 minutes, qualify as weapons.
• Under 18 U.S.C. § 921(a)(3)(B), the terms "frame" and "receiver" are also artifact nouns that may describe not-yet-complete objects.
• The Court found statutory support for this in 18 U.S.C. § 923(i), which requires serialization of frames or receivers for unconventional items like silencers, implying the terms encompass more than just prototypical finished frames.
• The Court rejected the rule of lenity and constitutional avoidance because the statute's "text, context, and structure" provide a clear answer (*Van Buren v. United States*).
• Regarding NFA concerns, the Court noted that AR-15 receivers do not qualify as machinegun receivers under current ATF interpretation and GCA analysis does not grant authority to regulate them as such under the NFA.