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By: Nick Grossardt, Volume 107 Staff Member

At the end of January 2023, the Bureau of Alcohol, Tobacco, Firearms, and Explosives (BATFE) promulgated a final rule outlining a series of factoring criteria for regulating firearms with affixed “stabilizing braces.”[1] Various models of these braces had been evaluated by the BATFE’s Firearms and Ammunition Technology Division (FATD) since 2012, with some resulting in the weapons being classified as pistols and the majority being classified as National Firearms Act (NFA) firearms.[2] After a number of designs eventually reached the market (many without evaluation, much less FATD clearance), the BATFE acted on a concern that the majority of these braces were really intended to evade the registration and taxation requirements that attach to certain classifications of weapons and other devices.[3] As Congress has enacted statutory restrictions on these classes of weapons, ostensibly for public safety reasons, the rule change seems within the BATFE’s general authority. However, the impending illegality of ownership for items that had been legally purchased raises a host of legal questions, some of which this Post will examine.


The NFA,[4] enacted in response to a Prohibition-era increase in organized crime,[5] set registration and taxation requirements for legal ownership and transfer of a variety of firearms.[6] Among the regulated categories were machine guns, short-barreled shotguns, and short-barreled rifles.[7] Failure to comply could lead to fines, prison, and forfeiture of the violating firearm.[8] This registration scheme was intended to restrict access to the sorts of weapons preferred by the criminals of the day. Following the high-profile assassinations of Dr. Martin Luther King, Jr. and Robert F. Kennedy,[9] Congress enacted the Gun Control Act of 1968 (GCA).[10] This act added some further definitions (such as “handgun”) and codified the short-barreled firearm provisions in Title 18 as well.[11] These definitions have not been substantially updated since 1934, and the BATFE, under various names and parent departments, has been responsible for enforcement.

Pertinent to this discussion is the consistent criterion that a “rifle” is intended to be fired from the shoulder. Why does this matter? The initial stabilizing braces were designed and evaluated with the user’s wrist or forearm being used as rearward support, with a cuff and straps securing the weapon in place.[12] This essentially forces a user to fully extend their shooting arm to align the weapon’s sights with their visual axis for accurate shooting, much in the same manner as a typical pistol or handgun stance. In contrast, a shouldered weapon does not require an extended shooting arm to produce the same line of aim. This instead provides a solid point of contact with the user’s torso and yields enhanced stability, recoil control, and accuracy. Thus, weapons that would otherwise be considered “rifles” but have a stabilizing brace instead of a stock may no longer fall into that category; if such weapons are not rifles, they are not subject to the NFA’s minimum barrel length restrictions.[13]

The FATD saw many purported brace designs over the past decade. After the FATD determined that the first submitted design may have had a valid use for disabled veterans, additional companies started submitting similar designs for evaluation. After receiving several questions as to whether such braces could be used to fire a weapon from the shoulder, the BATFE issued an Open Letter to the public to provide some guidance.[14] This guidance stated that braces designed to assist with single-handed firing were not considered shoulder stocks and would therefore not convert the weapon to an NFA firearm.[15] However, it also provided that intending to use a brace or redesigning a brace for use as a as a shoulder stock on a pistol would produce an NFA firearm subject to registration requirements.[16] Mixed messaging on what sorts of features would deem something to be redesigned or intended for use as a shoulder stock produced more questions and a further 2017 “clarification” that incidental shouldering would not automatically produce an NFA firearm.[17] This led to more confusion, however, and ultimately prompted the BATFE to propose rules for classifying weapons with these accessories. The final rule ultimately settled on a requirement for rearward surface area that allows firing from the shoulder, plus several other factors indicating that the weapon is intended to be used that way.[18]

In a sense, the volume of questions addressed to the FATD concerning firing “pistols” with “stabilizing braces” from the shoulder gave away the plot. Though “the original maker of the ‘stabilizing brace’ marketed it in 2012 and 2013 to assist persons with disabilities or limited mobility,”[19] the general trend of designs moved towards including more and more features of traditional shoulder stocks, and manufacturers began marketing firearms incorporating those designs as usable in that manner.[20] As a result of this marketing, over three million of these braces are in circulation, [21] with many of them attached to weapons that would otherwise be considered short-barreled rifles.


While the BATFE has legitimate concerns that federal statutes are being evaded, the final rule unsurprisingly provoked criticisms when it was announced. As is generally the case when an agency takes an action that individuals disagree with, the BATFE’s authority under the APA to make such a change was questioned. The final rule shifted from the notice of proposed rulemaking issued in 2021, which laid out a factoring test with point values intended to allow the industry to estimate whether a given brace design would create a rifle or not. The worksheet containing this test was criticized on multiple grounds, such as arbitrariness of the criteria chosen.[22] These complaints led to the final rule ultimately adopting only a subset of the criteria, focusing almost exclusively on whether a design was intended to facilitate firing from the shoulder.[23] However, because the final rule uses criteria previously identified and further narrowed the list to the most relevant factors addressing the stated problem,[24] it likely will be seen as a logical outgrowth of the proposed rules and should survive any argument that a new notice-and-comment period is required.[25]

In addition, commentors mentioned a handful of potential constitutional issues. As firearms are involved, comments naturally claimed the possible infringement of Second Amendment rights.[26] However, given the particular concern that Congress apparently had regarding short-barreled rifles in both the NFA and GCA, this argument is likely to fail. Certain types of “dangerous and unusual weapons” were determined to fall outside the scope of Second Amendment protections in District of Columbia v. Heller; [27] short-barreled rifles would probably fall within this category.

Another potential issue raised regarded unconstitutional takings under the Fifth Amendment.[28] This is also likely to fail on at least a couple grounds. First, takings only apply to protectable property interests. If one doesn’t have a legal right to own an NFA firearm, either by choosing to not register said firearm or due to some other legal prohibition, seizure or surrender of the firearm isn’t a Fifth Amendment violation. In essence, one cannot lose a right that they never had in the first place. Second, there are avoidance mechanisms: owners can either register the offending firearm using the BATFE’s Form 1,[29] or they can modify the weapons to keep them from falling under the “firearm” category of 26 U.S.C. §5845(a). Under either scenario, no seizure or surrender would have to occur.

Another potential concern regards NFA registration. Wait times for a registration to process allegedly take up to a year, and the BATFE’s window for registering a preexisting weapon that is reclassified as a short-barreled rifle under the new rule is set to close on May 31, 2023, four months after the rule’s issuance. This could lead to a situation where, even if one attempted to comply with the new rule by registering an offending firearm, that registration may not be processed before the May 31 deadline. This is particularly true if the volume of applications substantially increases due to the limited window in which preexisting weapons can be legally registered. Though the BATFE indicates that all applications submitted prior to May 31 will be honored,[30] this doesn’t account for any potential issues with the system, lost applications, or clerical errors that are not identified and corrected within the specified window. Punishing legitimate good-faith compliance efforts that were foiled by bureaucratic backlog might be legally acceptable, but it would be a bad look.


While the BATFE’s rule change may have resolved some confusion of the agency’s own making and closed a potential loophole, there are some concerns around the way it came about. The general concept of forcing a post-purchase surrender, modification, or registration of an item when that had not been a requirement at the time of purchase just seems somehow wrong. At the same time, some, perhaps even most, of these items had been specifically marketed as a way to evade federal law,[31] so sympathy might be misplaced in those cases.


[1] Factoring Criteria for Firearms with Attached “Stabilizing Braces”, 88 Fed. Reg. 6478 (Jan. 31, 2023) (to be codified at 27 C.F.R. pts. 478, 479).

[2] Id. at 6482.

[3] See id. at 6494 (“[T]hese ‘braces’ were being used with firearms extensively to create short-barreled rifles without following NFA requirements.”).

[4] National Firearms Act, ch. 757, 48 Stat. 1236 (1934) (codified as amended at 26 U.S.C. §§ 5801–49).

[5] See James A. D’Cruz, Half-Cocked: The Regulatory Framework of Short-Barrel Firearms, 40 Harv. J.L. & Pub. Pol’y 493, 496–97 (2017) (discussing the history of the NFA).

[6] 26 U.S.C. § 5841.

[7] See id. § 5845(a) (defining shotguns and rifles with barrel lengths under 18 and 16 inches respectively as “firearms” rather than “shotguns” or “rifles,” thus subjecting them to registration).

[8] Id. § 5871–72.

[9] See D’Cruz, supra note 5, at 500.

[10] Gun Control Act of 1968, Pub. L. 90-618, 82 Stat. 1213 (codified as amended at 18 U.S.C. §§ 921–28 and scattered provisions of 26 U.S.C.).

[11] See 18 U.S.C. §§ 921(a)(6), (8).

[12] See Factoring Criteria for Firearms with Attached “Stabilizing Braces”, 88 Fed. Reg. at 6483 (providing images of the original 2012 submission).

[13] See 26 U.S.C. § 5845(a)(3–4) (classifying short-barreled rifles as “firearms” and bringing them under the purview of 26 U.S.C. §5841).

[14] See Factoring Criteria for Firearms with Attached “Stabilizing Braces”, 88 Fed. Reg. at 6487 (detailing attempts to resolve inconsistencies).

[15] Id. “NFA firearm” in this context refers to an article falling under the “Firearm” definition of the NFA. 26 U.S.C. § 5845(a).

[16] Factoring Criteria for Firearms with Attached “Stabilizing Braces”, 88 Fed. Reg. at 6487.

[17] See id. at 6491–92 (stating that some “undermining” of the brace’s purpose would be required to redesign the firearm for NFA purposes).

[18] These other factors are an overall weight and length consistent with rifles, a length of pull consistent with rifles, sights with eye relief requiring shouldering, necessity for cycle of operations, marketing materials, and likely use of weapon in the general community. See id. at 6511–12.

[19] Id. at 6560.

[20] See id. (stating that demand increased in 2017 when several other manufacturers created models that were “marketed to shoulder fire a firearm”).

[21] See id. (estimating “between 3 million and 7 million” firearms in circulation, with the actual number being “closer to 3 million”).

[22] See id. at 6513 (citing comments alleging that the factoring criteria were “arbitrary or too complicated to understand”).

[23] See supra note 18 and accompanying text.

[24] Id. at 6510.

[25] See, e.g., Am. Med. Ass’n v. United States, 887 F.2d 760, 767 (1989) (“[A] final rule is not invalid for lack of adequate notice if the rule finally adopted is ‘a logical outgrowth’ of the original proposal.”).

[26] Factoring Criteria for Firearms with Attached “Stabilizing Braces”, 88 Fed. Reg. at 6548.

[27] 554 U.S. 570, 627 (2008).

[28] Factoring Criteria for Firearms with Attached “Stabilizing Braces”, 88 Fed. Reg. at 6549.

[29] Registration in this manner also includes a standard background check to verify that the applicant is not prohibited from owning NFA firearms. See id. at 6558–59.

[30] Id. at 6559.

[31] See id. at 6544–45 (pointing out that a manufacturer’s website stated that braces were a way to “avoid NFA controls” and “Stiff Arm the Establishment”).