Supreme Court Upholds ATF Rule Regulating Weapon Parts Kits and Unfinished Frames or Receivers as “Firearms”

By Cameron Schlagel and V.R. Bohman

In a significant ruling, the Supreme Court affirmed the authority of the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) to regulate weapon parts kits and unfinished frames or receivers as “firearms” under the Gun Control Act of 1968 (GCA). The decision in Bondi v. VanDerStok clarifies the scope of the GCA, determining that certain kits and unfinished firearm components can be classified as firearms and thus subject to regulation.¹

Background

The case arose from a challenge by firearm manufacturers and others against the ATF’s final rule defining the term “firearm” to include some partially complete, disassembled, or nonfunctional frames or receivers and weapon parts kits.² A “frame” or “receiver” is the principal component of a firearm “which provides housing for the hammer, bolt or breechblock, and firing mechanism, and which is usually threaded at its forward portion to receive the barrel.”³ “Frame” refers to the principal component of a handgun, while “receiver” refers to the principal component of a rifle or shotgun. A “weapon parts kit,” in turn, is a collection of parts, usually including an unfinished frame or receiver, that the consumer can assemble or otherwise finish to make a functional firearm.⁴ These kits vary widely in completeness and in the amount of work required to finish them — some kits contain all the necessary components to build a functional firearm, while others require substantial effort and specialized tools to complete.⁵ 
 
The Plaintiffs argued that the ATF’s rule was inconsistent with the GCA’s definition of “firearm.” The United States District Court for the Northern District of Texas granted the Plaintiffs’ motion for summary judgment and vacated the rule. The Fifth Circuit Court of Appeals affirmed in part, vacated in part, and remanded the case. The Supreme Court granted certiorari to resolve the issue.⁶

Supreme Court Opinion

Justice Gorsuch delivered the opinion of the Court, joined by Chief Justice Roberts and Justices Sotomayor, Kagan, Kavanaugh, Barrett, and Jackson. The Court held that the ATF rule treating certain weapon parts kits and unfinished frames and receivers as “firearms” was not facially inconsistent with the GCA’s definition of “firearm.”
 
At the outset, according to the Court, the case did not ask it to resolve whether ATF’s rule “may be lawfully applied to particular weapon parts kits or unfinished frames or receivers.”⁷ Instead, the Court assumed that the nature of the challenge was a “facial” pre-enforcement challenge, because the Plaintiffs did not dispute that assessment in their briefs.⁸ This part of the decision proved to be consequential, because the standard for a facial challenge is notoriously difficult to meet. Under that standard, the Plaintiffs had the burden to show that ATF’s regulation is inconsistent with the GCA on its face,⁹ meaning “the challenger must establish that no set of circumstances exists under which the [statute] would be valid.”¹⁰
 
Turning to the merits, the Court focused on the ordinary meaning of the terms “weapon,” “frame,” and “receiver,” which it held can encompass an unfinished object designed to be “readily converted” into a functional firearm or a functional frame or receiver.¹¹ For instance, the Court examined one of the challenger’s products, the “Buy Build Shoot” kit, which includes all necessary components to build a functional semiautomatic pistol.¹² According to the Court, the kit can be assembled in approximately 21 minutes using common tools and publicly available instructions, demonstrating that it meets the criteria of being readily convertible into a functional firearm.¹³ The Court emphasized that the GCA’s definition of “firearm” includes items that may be readily converted into operable weapons, reflecting Congress’s intent to regulate a range of firearm-related products that are not yet operable firearms in the common sense.¹⁴ The Court further noted that its interpretation of the GCA’s definition of “firearm” to include weapon parts kits and unfinished frames or receivers, provided they can be readily converted into functional firearms, aligns with Congress’s goal to prevent the proliferation of untraceable firearms and ensure that firearm regulations keep pace with advancements in technology and manufacturing.¹⁵

Concurring and Dissenting Opinions

Justice Sotomayor filed a concurring opinion, emphasizing that the ATF’s rule should not create difficulty for entities seeking to comply with the GCA.¹⁶ Justice Kavanaugh also filed a concurring opinion, highlighting his concerns about due process in individual cases and emphasizing the mens rea elements that must be shown to prove a violation of the GCA.¹⁷ Justice Jackson concurred, highlighting the limited scope of the judicial review in this case.¹⁸
 
Justice Thomas filed a dissenting opinion, arguing that the terms “frame” and “receiver” do not cover unfinished frames and receivers, and that weapon parts kits themselves do not meet the statutory definition of “firearm.”¹⁹ He emphasized that the ordinary meaning of “frame” and “receiver” does not include objects that may be “converted” into a frame or receiver.²⁰ This interpretation, according to Justice Thomas, is supported by the relevant provision of the GCA, § 921(a)(3), which confirms that objects that are not yet frames or receivers do not meet the statutory definition.²¹ The same reasoning, according to Justice Thomas, means that a weapon parts kit also cannot be a “firearm” under the GCA.²² Justice Thomas warned that the majority’s reasoning could expose manufacturers, sellers, and owners of commonly-used semiautomatic rifles to criminal liability under the National Firearms Act.²³ 
 
Justice Alito also dissented, expressing concerns about the application of the “facial” challenge test to regulatory challenges under the Administrative Procedure Act.²⁴ He argued that applying the “facial” challenge test — which usually applies in constitutional challenges to statutes — is unfair and was not the focus of the briefing or argument in the case.²⁵ Justice Alito further warned that this approach could have far-reaching consequences for the administrative state, as it would make it extremely difficult for plaintiffs to succeed in challenging any regulation prior to enforcement.²⁶

Implications

The Supreme Court’s decision has significant implications for the regulation of firearm-related products. By upholding the ATF’s authority to regulate weapon parts kits and unfinished frames or receivers, the ruling reinforces the agency’s ability to address the proliferation of untraceable firearms. The decision also clarifies the permissible scope of the GCA, providing guidance to manufacturers, dealers, and law enforcement agencies on the regulatory requirements for firearm-related products.

Because the Court did not rule on the validity of ATF’s rule as applied to specific products, this decision will likely prompt further challenges and litigation as the ATF continues to enforce its regulations. Additionally, the decision highlights ongoing debates about the interpretation of the GCA and the extent of the ATF’s regulatory authority.