The Bureau of Alcohol, Tobacco, Firearms and Explosives posted 21 proposed and final rules to the Federal Register on May 6, formally opening the public comment period on the broadest regulatory rollback in the agency's modern history — including notices to repeal the Biden-era pistol brace rule and the 2024 "engaged in the business" dealer definition expansion, Bearing Arms reported Tuesday.

The pistol brace notice of proposed rulemaking would formally rescind ATF's 2023 rulemaking that reclassified millions of pistol-braced firearms as short-barreled rifles subject to the National Firearms Act, requiring registration, a $200 tax stamp, and compliance with NFA transfer rules. Multiple federal circuits had already enjoined or vacated that rule on Administrative Procedure Act grounds; the formal NPRM now clears the regulatory record by initiating an official repeal through notice-and-comment rulemaking. A companion interim final rule simultaneously moves to rescind the 2024 "engaged in the business" expansion — which dramatically broadened the definition of who must hold a Federal Firearms License and conduct background checks on every transfer, effectively treating many private sellers as licensed dealers.

Also published in Tuesday's batch: a rule updating the federal machine gun definition to remove the bump stock language ATF relied upon before the Supreme Court's 2024 Cargill decision struck it down, and a proposed rule allowing NFA firearms makers to adopt markings previously placed on a firearm, simplifying compliance for manufacturers and NFA trusts that take over or modify serialized NFA items. That markings rule, published as Federal Register document 2026-08915, carries a written-comment deadline of July 6, 2026.

The Second Amendment Foundation announced May 5 that it had begun a detailed review of all 21 proposed changes, per a statement on SAF.org, and said it intends to file formal comments before the applicable deadlines. Gun Owners of America has also published a rule-by-rule breakdown, with GunsAmerica covering the GOA analysis and urging members to participate in the comment process. For FFL holders and manufacturers, the "engaged in the business" repeal is among the most operationally significant elements of the package: restoring the pre-2024 definition would clarify that standard private-party transactions do not require FFL licensing.

ATF Director Robert Cekada, confirmed April 29 alongside the announcement of the full 34-rule package, described the initiative as the most significant modernization of agency regulations in the bureau's history. With the rules now in the Federal Register, the 90-day public comment period is the primary mechanism for gun owners, dealers, and industry groups to shape the final text before rules are finalized. Full rule texts and comment submission portals for each docket are available on regulations.gov; 2A organizations are expected to file substantive comments on the pistol brace and dealer-definition proposals ahead of the deadlines.