The Pistol Brace Rule: Where the Litigation Actually Stands

As of this writing, the ATF’s 2023 pistol brace rule has been vacated by a federal district court for more than two years, has never survived a single appellate merits ruling against it, and is now the subject of the agency’s own proposal to erase it from the Code of Federal Regulations. That’s a proposal whose public comment period closed August 4, 2026, two days after this piece published. None of that means the underlying question is fully closed. Here’s what’s actually confirmed, case by case, and what still isn’t.

What’s Actually Vacated, and What Isn’t

The rule at issue took effect in early 2023 and applied a six-factor weighted test — length, weight, attachment method, whether the accessory was designed and marketed as a shoulder stock, and so on — to decide when a pistol fitted with a “stabilizing brace” should legally be treated as a short-barreled rifle (SBR) under the National Firearms Act. That classification matters because an SBR requires NFA registration and a tax stamp, where an ordinary braced pistol does not. Courts have since found that test unworkable to apply consistently, and as a practical matter it is not currently being enforced. But “vacated by a court and unenforced” is a different status than “formally removed from federal regulations,” and as of this piece’s publish date, the second part hasn’t happened yet. The regulatory text is still sitting in the CFR pending the rulemaking process described below.

Mock v. Bondi: The Case That Ended Enforcement

The case that actually did the work is Mock v. Garland — later restyled Mock v. Bondi after the change in DOJ leadership — filed in the U.S. District Court for the Northern District of Texas (No. 4:23-cv-00095) by plaintiffs William Mock, Christopher Lewis, Maxim Defense Industries, and the Firearms Policy Coalition. In August 2023, a Fifth Circuit panel granted a preliminary injunction protecting the named plaintiffs and FPC’s members, finding they were likely to succeed on their argument that the rule violated the Administrative Procedure Act. On June 13, 2024, District Judge Reed O’Connor went further at the summary-judgment stage. He vacated the rule in full, ruling that ATF’s six-factor test was arbitrary, capricious, and impermissibly vague — in the court’s words, it made it “nigh impossible for a regular citizen to determine what constitutes a braced pistol.”

The government initially appealed that vacatur to the Fifth Circuit. That appeal was fully briefed and, by spring 2025, had been placed in abeyance at the government’s request while the new administration’s DOJ reviewed the rule. It didn’t come back for a merits ruling. The parties filed a joint stipulation of dismissal on July 17, 2025, and the court entered the dismissal order on July 25, 2025 — ending the appeal and leaving Judge O’Connor’s vacatur as the last word from that case.

The Same Result in North Dakota

Mock wasn’t the only track. A separate case, Firearms Regulatory Accountability Coalition, Inc. v. Garland, brought by a 24-state coalition in the District of North Dakota, took a different procedural path to a similar conclusion. After the district court initially denied a preliminary injunction, the Eighth Circuit reversed that denial on August 9, 2024, agreeing that the rule’s criteria were unclear enough to make compliance “nearly impossible” for an ordinary gun owner to determine, and sent the case back to the district court to reconsider injunctive relief. By spring 2025, that district court had stayed its own proceedings pending the outcome of Mock, on judicial-economy grounds. This piece could not confirm a public docket update on the North Dakota case specifically since Mock’s July 2025 dismissal — see the note below.

ATF’s Own Move to Repeal the Rule

On May 6, 2026, ATF published a formal Notice of Proposed Rulemaking in the Federal Register proposing to remove the 2023 rule’s factoring criteria altogether and revert to the pre-2023 statutory definition, without the added six-factor test. The notice is unusually candid about why: it states that “because of the ongoing litigation and the various injunctions, for all intents and purposes, ATF has never actively enforced the 2023 final rule.” In effect, the agency is proposing to formally codify what the courts already ordered rather than continuing to defend a rule it concedes it hasn’t been able to enforce. The public comment period on that proposal runs through August 4, 2026.

This is a factual case timeline, not an illustrative example — dates and filings are drawn from court dockets, party press releases, and the Federal Register notice cited in the build note below.

What’s Still Unresolved

Three things are worth being precise about rather than rounding up to “the rule is dead.” First, the rule is vacated and unenforced in practice, but it has not yet been formally struck from the CFR. That only happens if and when ATF finalizes the May 2026 rulemaking, and the comment period on that proposal hadn’t even closed as of this piece’s publish date. Second, this piece could not independently confirm the current docket status of the North Dakota FRAC case following Mock’s July 2025 dismissal. It may have been dismissed, stayed indefinitely, or resolved some other way, and readers relying on that case specifically should check the current docket rather than this summary.

Third, no ruling here forecloses a future ATF, under a future administration, from proposing a new brace rule written to avoid the vagueness and APA problems that sank this one. None of that changes the current, confirmed bottom line: braced pistols are not being treated as SBRs requiring registration or a tax stamp right now. It does mean “right now” is doing real work in that sentence.