Handguns, Stabilizing Braces, and Related Components
Updated April 19, 2021
Handguns, Stabilizing Braces, and Related Components
On April 7, 2021, the White House announced that the
brace. ATF submitted that this cheek rest, when fully
Department of Justice has been directed to issue a proposed
extended, constituted a shoulder stock, because its “length
rule within 60 days (by June 6, 2021) to clarify when a
of pull” was greater than 13.5 inches (i.e., the distance from
device marketed as a stabilizing brace might turn a pistol
the trigger pad to the end of the cheek rest fully extended).
into a short-barreled rifle. On December 18, 2020, the
The defendant was found not guilty by a jury, based partly
Bureau of Alcohol, Tobacco, Firearms and Explosives
on ATF’s failure to take the measurement properly in
(ATF) published guidance in the Federal Register for
alignment with the barrel’s axis. This case is an example of
public comment that indicated that it was preparing to
how the absence of definitive determinations about the
reclassify certain heavier, larger handguns (pistols)
legality of firearms equipped with stabilizing braces and
equipped with stabilizing braces as more stringently
similar devices may create repercussions.
regulated short-barreled rifles. Such a reclassification
would retroactively trigger the more extensive paperwork
GCA- and NFA-Regulated Firearms
and background check requirements of the 1934 National
When Congress passed the GCA, it significantly amended
Firearms Act (NFA), and require registration of the owner
and repassed the NFA as Title II of that measure. These acts
and firearm with ATF. While this guidance was withdrawn
include different, but respective definitions for the term
on December 23, 2020, the proposed rule could address
“firearm” (18 U.S.C. §921(a)(3) and 26 U.S.C. §5845(a)).
some of the same issues.
Under these definitions, all firearms regulated under the
NFA are first regulated under the GCA. As discussed
Stabilizing Brace: Shooter’s Assist or
below, the three basic types of firearms regulated under the
Shoulder Stock?
GCA are shotguns, rifles, and handguns.
Stabilizing braces are devices that can be attached to the
rearward portion (breech) of a handgun or other pistol grip
SBSs, SBRs, AOWs, and DDs
firearm’s frame or receiver. The brace extends backwards,
The NFA further regulates short-barreled shotguns, or
generally in alignment with the axis of the barrel(s), so the
SBSs, and short-barreled rifles, or SBRs: (1) shotguns with
firearm can be secured to the shooter’s forearm, while it is
barrels less than 18 inches in length, (2) rifles with barrels
held by its pistol grip or other short stock, making a
less than 16 inches in length, or (3) any existing shotgun or
heavier, larger short-stocked firearm easier to handle. The
rifle that has been modified to be less than 26 inches in
first prototype stabilizing brace was designed to assist a
overall length by shortening its stock and/or barrel(s). (See
veteran and service-connected amputee with firing an AR-
18 U.S.C. §§921(a)(6) and (8), and 26 U.S.C. §5845(a).)
type handgun singlehandedly. Stabilizing braces and similar
devices, however, could serve more generally as a quasi-
Under “any other weapon,” or AOW, the NFA regulates
shoulder stock. The addition of shoulder stock to a short-
smoothbore handguns (less than 26 inches in overall length)
stocked firearm could possibly change a firearm’s
and other “concealable” firearms with combination
classification under current law due to definitional
smoothbore and rifled bore barrels between 12 and 18
differences between the NFA and Gun Control Act of 1968
inches in length. The AOW classification also captures
(GCA).
certain deceptive or disguised firearms (e.g., umbrella, belt
buckle, and pen guns). The term “any other weapon” is
ATF has long ruled that the attachment of a shoulder stock
defined at 26 U.S.C. §5845(e).
to a handgun or pistol grip firearm transformed that GCA-
regulated firearm into an NFA-regulated short-barreled rifle
Under “destructive device,” or DD, the NFA regulates
or shotgun. In November 2012, however, ATF determined
“non-sporting” shotguns; firearms with barrel bore
that attaching a stabilizing brace to an AR-type pistol would
diameters greater than one-half inch (e.g., grenade
not change that firearm’s classification from a solely GCA-
launchers, bazookas, and mortars); as well as grenades,
regulated handgun to an NFA-regulated short-barreled rifle.
rockets, mortar rounds, mines, and other explosive devices
Since then, many variations of stabilizing braces have been
(e.g., Molotov cocktails). Congress included similar
manufactured and sold in the United States. In 2015, in an
definitions for the term “destructive device” in the GCA
Open Letter, ATF raised questions as to the legality of
and NFA (18 U.S.C. §921(a)(4) and 26 U.S.C. §5845(f)). In
using or intending to use stabilizing braces as shoulder
addition, the NFA regulates machine guns and firearms
stocks. In several private letters, made public by the
silencers, which are beyond the scope of this In Focus.
addressees, ATF appeared to walk back these
considerations. In 2018, however, ATF charged an
Shotgun and Rifle Definitions
individual with unlawfully possessing an unregistered
Congress included identical statutory standalone definitions
short-barreled rifle—an AR-type pistol equipped with a
for the terms “shotgun” and “rifle” under the GCA and
cheek rest, which is arguably a variant of a stabilizing
NFA. The term “shotgun” means “a weapon designed or
https://crsreports.congress.gov
Handguns, Stabilizing Braces, and Related Components
redesigned, made or remade, and intended to be fired from
requirements, which includes remitting a $200 making tax.
the shoulder and designed or redesigned and made or
However, a handgun with equivalent dimensions does not
remade to use the energy of an explosive to fire through a
trigger the NFA requirements, as long as a shoulder stock is
smooth bore either a number of ball shot or a single
never affixed to its frame or receiver.
projectile for each single pull of the trigger” (18 U.S.C.
§921(a)(5) and 26 U.S.C. §5845(d)). The term “rifle”
The same is true for pistol grip firearms. However, ATF
means “a weapon designed or redesigned, made or remade,
holds out the possibility of reclassifying pistol grip firearms
and intended to be fired from the shoulder and designed or
as AOWs under the NFA if they are ever used in a
redesigned and made or remade to use the energy of an
concealed manner in the commission of a crime. Others
explosive to fire only a single projectile through a rifled
counter that pistol grip firearms would be more properly
bore for each single pull of the trigger” (18 U.S.C.
classified as DDs, under ATF’s reasoning that these short-
§921(a)(7) and 26 U.S.C. §5845(c)).
stocked, smoothbore firearms are “non-handguns” and
“non-shotguns,” and are usually firearms with barrel bores
From these definitions, it can be deduced that the defining
of greater than one-half inch in diameter.
characteristic of a long gun (shotgun or rifle) is that it is
intended to be shoulder-fired, from which it follows that the
Larger, Heavier Handguns, and Pistol
defining feature of a long gun is a shoulder stock of some
Grip Firearms
type. In addition, shotguns are “smoothbore.” The barrel of
In the past 16 years, firearms manufacturers in the United
a rifle is “rifled bore,” and consists of lines and grooves
States have successfully marketed certain larger, heavier
machine-cut into the interior of the barrel (the bore) to spin
handguns and other pistol grip firearms that arguably push
a bullet as it travels at a high velocity down the barrel bore.
the limits of current law definitions of firearms types and
classes under current law. Some of these handguns are
Handgun Definition and Other Pistol Grip Firearms
assembled around frames and receivers originally designed
Under the GCA, the term “handgun” means “(A) a firearm
for AR- and AK-type rifles, and are sometimes chambered
which has a short stock and is designed to be held and fired
for mid-size rifle cartridges and shotgun shells.
by the use of a single hand; and (B) any combination of
parts from which a firearm described in subparagraph (A)
Under the 1994-2004 Semiautomatic Assault Weapons
can be assembled” (18 U.S.C. §921(a)(29)). From this
(SAW) ban, some of these handguns could have been
definition, it can be deduced that the defining feature of a
prohibited under its 50 ounce weight limit (unloaded) and
handgun is its short stock, and that it is designed to be fired
other characteristics that defined an “assault pistol.” The
singlehandedly. The term handgun includes both pistols and
SAW ban did not address pistol grip firearms substantively,
revolvers (26 C.F.R. §§478.11 and 479.11). Under current
as many of these firearms were pump-action, as opposed to
law, rifled bore handguns are regulated solely under the
semiautomatic, when the ban was enacted. The introduction
GCA and there are no restrictions on the barrel or overall
of stabilizing braces and similar components has
length of such handguns.
significantly increased the popularity of heavier, larger
pistols and pistol grip firearms.
Smoothbore handguns are regulated under the NFA under
the AOW classification. Since at least 1976, however, ATF
In the past eight years, larger, heavier handguns and pistol
has adopted 26 inches in overall length as the determining
grip firearms have seen increased sales likely due, in no
dimension that separates NFA-regulated “concealable”
small part, to stabilizing braces. Most major firearms
smoothbore handguns, or AOWs, from GCA-regulated
manufacturers are making firearms equipped with
short-stocked, smoothbore firearms. ATF adopted this
stabilizing braces as part of their featured product lines.
presumptive dimension of concealability from the statutory
While there are no available statistics to gauge
definitions for short-barreled rifles and shotguns discussed
authoritatively the number of stabilizing braces already
above. ATF refers to these solely GCA-regulated short-
made and sold in the United States, unofficial estimates
stocked, smoothbore firearms, which are greater than 26
suggest that there are between 10 and 40 million stabilizing
inches in overall length, as “pistol grip firearms.” The
braces and similar components already in civilian hands,
popularity of pistol grip firearms arguably increased in
either purchased as accessories or already attached to
2008, when ATF determined that the barrel length was
firearms made at home or at the factory. Altering the
“immaterial” to the classification of such firearms, while
classification of firearms equipped with stabilizing braces
the 26 inches in overall length restriction remained
would likely affect millions of owners.
unchanged. Prior to this, most firearms makers believed that
the barrel of a pistol grip firearm had to be greater than 18
Today, some firearms enthusiasts view GCA-regulated
inches.
handguns and pistol grip firearms equipped with stabilizing
braces as viable alternatives to the more strictly NFA-
“Gray Area” in the Law?
regulated short-barreled rifles and shotguns. At the same
In a potentially legal gray area, some GCA-regulated
time, gun control advocates have called on ATF to reverse
handguns and pistol grip firearms are dimensionally
its determinations with regard to stabilizing braces, as well
equivalent—in terms of their barrel lengths, overall lengths,
as, larger, heavier handguns and other pistol grip firearms.
and/or barrel bores—to other NFA-regulated firearms. As
They view such firearms as “assault pistols” or “assault
discussed above, it is unlawful to modify an existing rifle or
shotguns,” and have called on Congress to reconstitute an
shotgun by shortening its stock and/or barrel(s) into a short-
assault weapons ban.
barreled rifle or shotgun without following the NFA
https://crsreports.congress.gov
Handguns, Stabilizing Braces, and Related Components
William J. Krouse, Specialist in Domestic Security and
Crime Policy
IF11763
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