In a press release issued on March 23, 2018, Attorney General Sessions announced issuance of a notice of proposed rulemaking clarifying that bump stocks fall within the definition of “machinegun” under federal law.  Officials from the Bureau of Alcohol, Tobacco, Firearms and Explosives (“ATF”) advise the notice will be published in the Federal Register later this week.  This bulletin will summarize the Administration’s proposal to ban bump stocks and the impact on possessors if the proposals are adopted.

What is a Notice of Proposed Rulemaking?

A notice of proposed rulemaking (“NPRM”) is a document published in the Federal Register announcing to the public that a federal agency wishes to make changes to a regulation.  Publication of the notice is required under the Administrative Procedure Act (“APA”) before an agency may implement regulation changes.  The APA generally requires that agencies publish proposed regulation changes, solicit public comment, consider all comments, and then publish a final rule.  Until the final rule is published and effective, existing regulations remain in place.

Summary of Bump Stock Proposal

The NPRM outlines the October 1, 2017, shooting in Las Vegas, Nevada, in which the shooter used AR-type rifles with attached bump-stock-type devices.  The notice states that the devices were readily available in the commercial marketplace through online sales directly from the manufacturer and through multiple retailers.

The NPRM states that during the period 2008-2017 ATF issued classification decisions concluding that certain bump-stock-type devices were not machineguns, including a classification issued to the manufacturer of the devices used in the Las Vegas shooting.  The NPRM then states as follows:

Those decisions did not include extensive legal analysis relating to the definition of “machinegun.” Nonetheless, they indicated that semiautomatic firearms modified with these bump-stock-type devices did not fire “automatically,” and were thus not “machineguns,” because the devices did not rely on internal springs or similar mechanical parts to channel recoil energy.  ATF has now determined that that conclusion does not reflect the best interpretation of the term “machinegun” under the GCA and NFA. In this proposed rule, the Department accordingly interprets the definition of “machinegun” to clarify that all bump-stock-type devices are “machineguns” under the GCA and NFA because they convert a semiautomatic firearm into a firearm that shoots automatically more than one shot, without manual reloading, by a single function of the trigger.

DOJ indicates that ATF issued 10 rulings between 2008 and 2017 that would effectively be overruled if the regulations are amended as proposed in the NPRM.  The NPRM states that the agency applied an incorrect interpretation of the term “automatically” as used in the definition of “machinegun” to the devices considered and classified.

DOJ states that banning bump-stock-type devices will significantly enhance public safety.  The NPRM notes that the Las Vegas shooting highlighted the destructive capacity of firearms equipped with the devices and the carnage they inflict.  The document further states that the shooting publicized the availability of the devices–potentially to criminals and terrorists–and increased the threat to public safety.  The purpose of the NPRM is to address that threat.

The NPRM proposes amending the definition of “machinegun” in regulations in 27 C.F.R. §§ 447.11, 478.11, and 479.11 to add the following language:

For purposes of this definition, the term “automatically” as it modifies “shoots, is designed to shoot, or can be readily restored to shoot,” means functioning as the result of a self-acting or self-regulating mechanism that allows the firing of multiple rounds through a single function of the trigger; and “single function of the trigger” means a single pull of the trigger.  The term “machinegun” includes bump-stock-type devices, i.e., devices that allow a semiautomatic firearm to shoot more than one shot with a single pull of the trigger by harnessing the recoil energy of the semiautomatic firearm to which it is affixed so that the trigger resets and continues firing without additional physical manipulation of the trigger by the shooter.

Impact of Amended Regulations on Possessors of Bump Stocks

The NPRM states that the proposed rule would overrule prior inconsistent classifications of bump-stock-type devices so that all qualifying devices would be regulated as machineguns.  Because machineguns manufactured after 1986 may not be lawfully possessed by persons other than law enforcement and the military, once the final rule is effective all bump-stock-type devices in the hands of consumers would be contraband.  Any such devices manufactured or imported after the effective date of the final rule must be marked, registered, transferred pursuant to ATF approval, and distributed only to law enforcement and the military.

ATF has in the past allowed possessors to register firearms that were reclassified.  See ATF. Rul. 94-1, 94-2, and 2001-1, available on ATF’s website at  Nonetheless, the NPRM states that DOJ has determined there will be no registration period for any device classified as a “machinegun” as a result of the NPRM and any final rule.  The NPRM states that if the final rule adopts the proposals set forth in the notice, current possessors of regulated devices must dispose of them.

Public Participation

In accordance with the APA, ATF is soliciting comments on the proposals.  In addition to the proposed regulatory language, the agency requests comments on the costs and benefits of the proposal and how the agency should address devices in the hands of private parties.  Comments will be accepted during the 90-day period following publication in the Federal Register.  Comments may be submitted through the online eRulemaking portal,; via fax at (202)648-9741, or through mail to Vivian Chu, Mailstop 6N-518, ATF, 99 New York Avenue, NE, Washington, DC 20226.  


The NPRM published by DOJ is a proposal only and does not at this time ban bump stocks.  Bump stocks will be banned only if DOJ publishes a final rule adopting the proposals outlined in the notice.  Interested parties, including manufacturers, dealers, and purchasers, may submit comments on the proposed regulatory changes.  ATF and DOJ are required by law to take the comments into account and address them before issuing a final rule.  

This bulletin is for informational purposes only and is not intended to be construed or used as legal advice. Receipt of this bulletin does not establish an attorney-client relationship.

Please contact me with questions about this bulletin at or (301)358-3553.