Can you shoulder an AR-15 pistol brace in 2019?

Posted by 80-Lower on Oct 31st 2019

Can you shoulder an AR-15 pistol brace in 2019?

For a little over two years, this question has sparked debate that rivaled the “ shoulder thing that goes up” debacle. At some point in 2014, AR-15 owners noticed that Sig Sauer introduced a “stabilizing brace” for AR-15 pistols. Originally intended to be strapped around the forearm for better recoil control, the brace started being used as a buttstock of sorts. Folks saw this unintended function as an opportunity to build a legal, pseudo-SBR with no paperwork: They would buy an 80 percent lower, build it, slap on a pistol upper, and throw a brace on their buffer tube. Boom, AR-15 pistol you can shoulder – or at least, could.

But it’s 2019 and the debate raged on until just recently. Can you still shoulder a pistol brace?

2014: ATF issues ruling on pistol braces

Angry politicians started crying foul of the Sig shoulder brace saga. So, the ATF released a statement to attempt to clarify the legality of this new, unofficial practice:

“For the following reasons, we have determined that firing a pistol from the shoulder would not cause the pistol to be reclassified as an SBR: FTB classifies weapons based on their physical design characteristics. While usage/functionality of the weapon does influence the intended design, it is not the sole criterion for determining the classification of a weapon. Generally speaking, we do not classify weapons based on how an individual uses a weapon.”

Basically, the ATF said no, shouldering a pistol brace does not make your AR-15 pistol a Short-Barreled Rifle (SBR) and thus, an NFA weapon. Some political leaders were quite unhappy at this clarification.

2015: The ATF writes a second opinion

To appease the ruffled feathers of anti-gunners and politicians, the ATF's own Max Kingery (then-acting Chief of Firearms Technology Criminal Branch), issued a second opinion:

“Any person who intends to use a handgun stabilizing brace as a shoulder stock on a pistol (having a rifled barrel under 16 inches in length or a smooth bore firearm with a barrel under 18 inches in length) must first file an ATF Form 1 and pay the applicable tax because the resulting firearm will be subject to all provisions of the NFA.”

Womp-womp. Except this ruling didn't last for long. Some federal lawyers must have advised the ATF that trying to re-classify a weapon system simply by holding it a certain way might be shaky ground in court.

2019: The ATF's "final" ruling

Tech Criminal Chief Kingery came around one last time to gift gun owners with a third and currently-final ruling about whether you can shoulder the pistol brace. Here it is, once and for all (for now):

“To the extent the January 2015 Open Letter implied or has been construed to hold that incidental, sporadic, or situational ‘use’ of an arm-brace (in its original approved configuration) equipped firearm from a firing position at or near the shoulder was sufficient to constitute a ‘redesign,’ such interpretations are incorrect and not consistent with ATF’s interpretation of the statute or the manner in which it has historically been enforced.” 

This makes the ATF’s final position on the matter quite clear: Incidental, sporadic, or situational use of an AR-15 pistol’s unmodified arm brace as a shoulder stock doesn't constitute the weapon in question being "redesigned" (and thus legally reclassified) as a short-barreled rifle or NFA item. Basically, shouldering a pistol brace "sometimes" isn’t illegal.

Can I still shoulder a pistol brace?

Yes, according to the ATF.

But with one big caveat: Don't show it off.

The words "incidental" and "sporadic" could be the ATF's way of saying, "This is a gray area and a political hot-button topic. We can't make a truly definitive ruling, one way or the other."

What does this ruling even mean, exactly? If we stick to English definitions, sporadic means, " Occurring at irregular intervals or only in a few places; scattered or isolated." So, you can do it, but we don't recommend you do it all the time.

Shaky but legal-for-now ground, indeed.


  • In 2014, the ATF said that shouldering a pistol didn’t make your AR-15 pistol an SBR.
  • In 2015, the ATF reversed. They said  using a brace as a stock constitutes a “redesign”, making your pistol an SBR.
  • In 2019, the ATF gave a ruling that says "incidental" and "sporadic" use of an arm brace as a buttstock isn't illegal.
  • You can shoulder a pistol brace, but the ruling is somewhat conditional and not a strict "always yes" or "always no".

DISCLAIMER: If you are new to the world of DIY gun building, you likely have a lot of questions and rightfully so. It’s an area that has a lot of questions that, without the correct answers, could have some serious implications. At, we are by no means providing this content on our website to serve as legal advice or legal counsel. We encourage each and every builder to perform their own research around their respective State laws as well as educating themselves on the Federal laws. When performing your own research, please be sure that you are getting your information from a reliable source.