March 26, 2025 – Today, the U.S. Supreme Court issued a decision  (“Opinion”) reversing the U.S. Court of Appeals for the Fifth Circuit and holding that the Bureau of Alcohol, Tobacco, Firearms and Explosives (“ATF”) has authority, pursuant to the Gun Control Act (“GCA”), to regulate firearms kits and unfinished frames and receivers.

The background of this lawsuit started in 2022, when the ATF “adopted a new rule designed to combat the proliferation of ghost guns” (“Rule”).  Opinion at 3.  The Rule included provisions that: (1) deemed “weapon parts kits ‘that [are] designed to or may readily be completed, assembled, restored, or otherwise converted to expel a projectile by the action of an explosive’” to be firearms subject to the GCA, Opinion at 4 (quoting 27 C.F.R. § 478.11); and (2) provided that a “‘frame or receiver” of a firearm subject to the GCA “should be understood to encompass as well ‘a partially complete, disassembled, or nonfunctional frame or receiver, including a frame or receiver parts kit, that is designed to or may readily be completed, assembled, restored, or otherwise converted to function as a frame or receiver,’” Opinion at 5 (quoting 27 C.F.R. §478.12(c)).

Prior to the Rule taking effect, various firearms industry members filed a facial challenge to the Rule, asserting that “the GCA cannot be fairly read to reach weapon parts kits or unfinished frames or receivers.”  Opinion at 5.  The U.S. District Court for the Northern District of Texas agreed with the firearms industry members and vacated the Rule’s provisions concerning firearms kits and unfinished frames and receivers. The Fifth Circuit affirmed that decision, holding that the Rule’s provisions as to firearms kits and unfinished frames and receivers are “facially inconsistent with GCA” and thus, invalid.  Opinion at 6.

The U.S. government sought review by the Supreme Court.  In a 7-2 decision, delivered by Justice Gorsuch, the Supreme Court reversed and upheld the validity of the Rule’s provisions concerning firearms kits and unfinished frames and receivers. As to firearms kits, the Supreme Court held that any firearms kit that is “capable of being readily . . . converted to expel a projectile by the action of an explosive” is subject to the GCA under the Rule.  Opinion at 12.  But the Supreme Court expressly recognized that “[j]ust because some kits . . . qualify as weapons that ‘can readily be converted’ into working firearms does not mean all do,” and the Supreme Court elected not to “untangle exactly how far” the Rule’s provision on firearm kits will reach.  Opinion at 13.  But the Supreme Court stated that a firearms kit that can be converted into a firearm “in less than an hour” “without specialized knowledge” and “using everyday tools” does fall under the Rule.  Opinion at 12.

The Supreme Court further held that “[t]he GCA reaches, and permits ATF to regulate, at least some ‘partially complete’ frames or receivers.”  Opinion at 17.  The Court cautioned that its ruling has limits and that it was not holding that “the GCA reaches, and ATF may regulate, any combination of parts susceptible of conversion into a frame or receiver with sufficient time, tools, and expertise,” as “[s]ome products may be so far from a finished frame or receiver that they cannot fairly be described using those terms.”  Opinion at 21.  But the Court again elected not to define the bounds of the Rule’s application to unfinished frames and receivers.

Given that the Supreme Court did not provide explicit limits on what firearms kits, unfinished frames, and unfinished receivers will fall outside the Rule, firearms industry members are likely to see continued legal challenges to the Rule on an as-applied basis to particular products.

Renzulli Law Firm will continue to monitor the application of the Rule and legal developments in the Firearms industry.  If you have any questions regarding the application of the Rule to your products, please contact John F. Renzulli or Christopher Renzulli.