Britto v. ATF was a federal lawsuit that killed the Bureau of Alcohol, Tobacco, Firearms and Explosives’ 2023 rule reclassifying pistols with stabilizing braces as short-barreled rifles. A federal district court in Texas vacated the rule on June 13, 2024, and the Fifth Circuit dismissed the consolidated Britto appeals as moot that August, since there was no longer a rule to enjoin.1Justia. Darren Britto v. Bureau of Alcohol, Tobacco, Firearms and Explosives For gun owners, the practical result is that braced pistols are no longer treated as short-barreled rifles under that rule, and no federal registration is required because of it.
What the Stabilizing Brace Rule Did
A stabilizing brace straps around the shooter’s forearm to steady one-handed firing of a large-format pistol. After the ATF initially approved these devices, millions of gun owners bought braced pistols on the understanding that no special federal registration was required.
On January 31, 2023, the ATF published Final Rule 2021R-08F, which declared that most pistols with attached stabilizing braces were actually short-barreled rifles (SBRs) under the National Firearms Act.2Federal Register. Factoring Criteria for Firearms With Attached Stabilizing Braces Federal law defines an SBR as a rifle with a barrel shorter than 16 inches, and SBRs are subject to registration, background checks, and historically a $200 federal tax.3Office of the Law Revision Counsel. 26 USC 5845 – Definitions
Owners had until May 31, 2023, to pick one of four options:
- Register the firearm by filing an ATF Form 1, with the $200 tax waived during the grace period
- Remove the stabilizing brace
- Destroy the firearm
- Surrender it to the ATF
Non-compliance meant possessing an unregistered NFA firearm, punishable by up to 10 years in federal prison and a $10,000 fine.4Office of the Law Revision Counsel. 26 USC 5871 – Penalties The ATF itself estimated the rule would sweep in millions of firearms.5Bureau of Alcohol, Tobacco, Firearms and Explosives. Information Regarding Pending NFA Forbearance Applicants Submitted Pursuant to the Vacated Final Rule 2021R-08F Pertaining to Stabilizing Braces
What the Plaintiffs Argued
Darren Britto, a military veteran, joined other plaintiffs in arguing that the ATF had exceeded its statutory authority. Their core claim was that Congress never authorized the agency to redefine what counts as a rifle and turn millions of lawful gun owners into felons through rulemaking.
The plaintiffs also attacked the rule on procedural grounds under the Administrative Procedure Act. The ATF’s proposed rule had used a point-based worksheet to decide whether a braced firearm qualified as an SBR. The final rule scrapped that worksheet and substituted a subjective six-factor balancing test. Commenters who responded to the worksheet, the plaintiffs argued, never had a real chance to weigh in on what the ATF actually adopted.6Justia. Mock v. Garland, No. 23-10319
A Second Amendment claim invoked the Supreme Court’s 2022 decision in New York State Rifle & Pistol Association v. Bruen, which requires firearms regulations to be consistent with America’s historical tradition of firearm regulation.7Supreme Court of the United States. New York State Rifle and Pistol Association Inc. v. Bruen Criminalizing possession of millions of commonly owned firearms, the plaintiffs said, had no historical parallel.
The ATF defended the rule as a reasonable interpretation of existing law. The agency argued that many braced pistols function like short-barreled rifles because they are designed to be fired from the shoulder, and that owners had multiple compliance paths available.
How the Courts Ruled
Fifth Circuit: The Rule Was Likely Unlawful
The first major appellate ruling came in August 2023 in Mock v. Garland, a related challenge consolidated with the Britto litigation. The Fifth Circuit reversed a district court’s denial of a preliminary injunction and found the plaintiffs likely to succeed on their APA challenge.8United States Court of Appeals for the Fifth Circuit. No. 23-10319 – Mock v. Garland
The court’s reasoning turned on the APA’s “logical outgrowth” doctrine. A final rule has to be a natural evolution of what the agency proposed. The ATF’s swap of a point-based worksheet for a subjective six-factor test was not, the court concluded, a logical outgrowth of anything the public had commented on.6Justia. Mock v. Garland, No. 23-10319 The court also held the rule was a legislative rule carrying the force of law, so full APA procedural compliance was required.
District Court: The Rule Is Vacated
On remand, the U.S. District Court for the Northern District of Texas held the rule violated the APA and ordered it vacated on June 13, 2024.9Justia. Britto et al v. Bureau of Alcohol, Tobacco, Firearms and Explosives The court relied on the Fifth Circuit’s finding that the rule was not a logical outgrowth of the proposed rule and had to be set aside as unlawful.
Vacatur under the APA is a universal remedy. Unlike an injunction that protects only named plaintiffs, vacating a rule strips it of legal force against everyone.10United States Court of Appeals for the Eighth Circuit. No. 23-3230 Once the order took effect, the stabilizing brace rule ceased to exist as an enforceable regulation nationwide.
Fifth Circuit: The Appeals Are Moot
On August 26, 2024, the Fifth Circuit dismissed the consolidated Britto appeals as moot. With the rule already vacated, a preliminary injunction would have added nothing to the relief the plaintiffs already had.1Justia. Darren Britto v. Bureau of Alcohol, Tobacco, Firearms and Explosives
What Brace Owners Should Know Now
Because the rule has been vacated, pistols with stabilizing braces are no longer classified as short-barreled rifles under it. Owners who never registered have no obligation to do so based on the brace rule.
Owners who did file an ATF Form 1 during the original compliance window faced a follow-up decision. The ATF told applicants they could either withdraw their application or let it be processed. Anyone who wanted to withdraw had to do so by November 10, 2025, through the eForms system or by emailing the ATF. Applications not withdrawn by that date would be processed as standard NFA filings.5Bureau of Alcohol, Tobacco, Firearms and Explosives. Information Regarding Pending NFA Forbearance Applicants Submitted Pursuant to the Vacated Final Rule 2021R-08F Pertaining to Stabilizing Braces
State law is a separate question. A handful of states ban short-barreled rifles outright regardless of federal status, and a few others allow them only under narrow exceptions. Federal vacatur of the brace rule does not override any state-level prohibition, so anyone building or possessing an actual SBR should verify their state’s rules independently.
Why the Case Matters Beyond Braces
The day after the district court vacated the brace rule, the Supreme Court issued Garland v. Cargill, striking down the ATF’s separate rule that had classified bump stocks as machine guns.11Supreme Court of the United States. Garland v. Cargill The Court held that a semiautomatic rifle equipped with a bump stock does not meet the statutory definition of a machine gun, because each shot still requires a separate function of the trigger.
The two decisions run on the same current. Congress defined “machine gun” and “rifle” in specific statutory terms, and the courts held the ATF to those definitions rather than to expansions the agency wrote by regulation. The Fifth Circuit’s logical-outgrowth analysis also gives future challengers a clear line of attack against agencies that propose one framework and finalize something materially different. Whether that reasoning spreads beyond Texas, Louisiana, and Mississippi will depend on litigation in other circuits, but for now the stabilizing brace rule stands as one of the most prominent federal firearms regulations struck down on procedural and statutory grounds in the post-Bruen era.