Arm Braces & Pistols Legal, Even When Fired From Shoudler

Alex Capp's shoots the SIG SB-15 from his shoulder.

Before you complain, yes I agree, TFB content has been too legal heavy in the past couple of weeks. But this morning when I got the ATF letter I thought it would be beneficial to the community to post it. This letter affirms that it is perfectly legal for a shooter to fire a firearm by resting an arm brace, such as the SIG SB15 stabilization brace, against their shoulder, just as it is legal to rest the rear part of a pistol, such as a AR-15 buffer tube, against the shoulder.  Alex Capps can be seen shooting the SB15 from his shoulder in the above photo (Alex used an SBR lower to ensure we were not inadvertently breaking the law, which in retrospect was unnecessary).

Here is the the full letter

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • MrPhantom

    I see literally no way this could backfire whatsoever.


    Not at all.

    • Andrew


      • Isaeus


        Sergeant Bradley posted his letter from BATFE on this morning in order to end the ceaseless threads about whether shoulder-firing an AR pistol with the device attached is lawful.

        I am grateful to him for writing his letter to BATFE and and posting their letter to him. And if Sig Sauer already requested that TFB post his letter here, I sure hope Sig has already offered him a free Sig AR-style pistol and brace of his choosing, as Sig surely will sell more of these things as a result of that letter.

    • ValleyForge77

      When you think about it, this is the only possible interpretation. If otherwise, would shooting a rifle with one hand all of a sudden then make it a pistol? Would shooting a pistol with two hands suddenly make it a short-barrel rifle? (as the definition of a pistol is ‘designed to be shot with one hand’). Would bump-firing a rifle make it full-auto? Numerous analogies like this that illustrate the picture well. It has to be based on what the implement was designed for, not one possible different usage instance. Ultimately it is not a stock and it does not make an SBR. Close, but no cigar. Not adjustable/collapsible, has an ‘open back’, straps on it, still can’t use a VFG, etc. And when you think about it too, SBR law is really outdated anyway. Is an SBR really that much different than a bullpup? It all gets to be a little mumbo jumbo after you really dig into it. Anyway, Just my .02c. I think it’s a sensible interpretation and doesn’t change the world or anything.

      • Cymond

        That’s how I understand it, that it’s all about how the gun was designed to be used, as shown by it’s features. (A shoulder stock is accepted as proof that the gun is designed to be fired from the shoulder.) Still, I’m really glad to see this clarified and put on paper from the aTF.

        So how far can we push this before it breaks? KAK Industries makes a buffer tube that increases the length-of-pull of the SB-15. I want to build a SB-15 pistol, but how much can the SB-15 be altered before it becomes “intended to be fired from the shoulder”? Does a special buffer tube, which makes the SB-15 longer, show intent to be fired from the shoulder???

        18 U.S. Code § 921 A “(7) The term “rifle” means a weapon designed or redesigned, made or remade, and intended to be fired from the shoulder and designed or redesigned and made or remade to use the energy of an explosive to fire only a single projectile through a rifled bore for each single pull of the trigger. “

      • gunslinger

        wait, using 2 hands to shoot a pistol is wrong? wow, i guess all those competition shooters are doing it wrong.

        even the cup and saucer grip…2 hands..

        ok i’ll stop now.

        • ValleyForge77

          That’s what you got out of that? …that I was saying that shooting a pistol with 2 hands is wrong? Uhhhh ok.

  • BryanS

    Generally speaking they do not classify a weapon based on how an individual uses that weapon, until it malfunctions with a slam fire and they railroad you through federal courts and ruin your life.

    • Spencer

      You mean the Olofson case? I think that was a hammer-follow issue and not a slamfire one. BTW the Wikipedia article on that case seems extremely biased against him.

      • BryanS

        Thats the one. There have been others, where they have modified a firearm in order to create the case they wanted.

      • Eric S

        If you read the court documents, he was an idiot. He built an AR pattern rifle off modified M16 lower parts and told the guy he was transferring too that it had an unmarked 3rd setting that would burst, then jam. Course the guy who tested the rifle tried this setting and proceeded to burst and jam the rifle. Thus he knowing transferred a firearm which could fire more than one round with a trigger pull.

    • David KEnik

      This is my article on the pistol brace. Mine is used on a pistol lower and I love it.

    • Geodkyt

      Based on UNREFUTED TESTIMONEY and EVIDENCE presented at trial, Olafson knowingly modified a gun so that it would go fully automatic. That gun (more specifically, the guts of the gun) WAS NOT in “factory original” condition, and in fact had had been modified to a condition that ATF publically warned YEARS before the gun was built could result in it firing automatically.
      The technical expert the defense called in to defend him (who is a really great guy, and a hell of a gunsmith, BTW) didn;t do Olafson any favors, because he didn’t actually ARGUE THE CASE AT HAND, and NEVER refuted the PHYSICAL, TESTIMONIAL, and DOCUMENTARY evidence the government had presented. He also threw out legally meaningless (and factually irrelevant) arguments to defend Olafson. (For example, using off the shelf, US manufactured to SAAMI-spec, by the BIGGEST ammunition manufacturers in the US, .223 Remington ammunition is not “fudging the test by choosing ‘soft primered’ ammo” — because the gun (LIKE ALL OLYMPIC AR15S BUILT AT THAT TIME) actually HAD a SAAMI-spec .223 Remington chamber, NOT a milspec 5.56mm NATO one. (IOW, using Gi ammo to test the gun would be “fudging the test” by using especially HARD primered ammo to cover up the failure mode.)
      And yes, I have read the ENTIRE court transcript.

      • Yep

        Your liberal use of caps lock really makes your statement look amateur at best.

        • Yes, and having to throw out formatting complaints, because you can’t actually refute anything that was said, makes your critique childish and irrelevant.

  • Michael R. Zupcak

    Earl Griffith sounds like a reasonable man

  • hami

    I wonder if the Sergeant was asking the ATF in an official capacity. As in, he saw someone doing it and wanted to know if he should arrest them.

    • BryanS

      I think the bulk of the readership will be skeptical if they can trust this or any other letter from the ATF. Personally, I take it with a grain of salt.

      A large one.

      That can subside a small village for a year.

    • It was on an official letterhead so it would be a department inquiry.

  • BryanS

    Steve, I think the bulk of the readership will be skeptical if they can trust this or any other letter from the ATF.

    • Suburban

      Was just watching a GunWebsites video earlier today, where it was explained that putting a cane tip on the end of pistol buffer tube, and resting that on your shoulder was deemed illegal by ATF. Rubber cap illegal, stock-looking thing legal?

      • Let me pass this on. If you modify the SB15 or any other stabilizing brace you just got yourself an SBR.
        I learned that should you remove the elastic and velcro part it’s now an SBR. I know it’s dumb but that’s what ATF says.

        • Cymond

          Yeah, I’ve heard that before, and it makes some sense. It won’t work as an arm brace without the straps, so it’s not really an arm brace anymore if you take them off. It’s only possible use then is as a shoulder stock.
          On the other hand, every SB-15 owner needs to be told this. It should be included as a warning in every package if it isn’t already.

          • I recently opened a box with a Century PAP with a brace and there wasn’t anything in the manual about mods to the brace.

          • Geodkyt

            It ought to be molded into the side of the brace itself, frankly.

        • Ed

          Can I put straps on an A2 stock and call that a brace? Kidding, not gonna do that.

    • It’s for real Bryan—I talked with Sig and the ATF today.

  • SH

    Not sure what’s going on in the picture… A pistol with arm-brace turned AOW with vertical grip? If that’s the case, why not go SBR and add real stock instead of brace?

  • aroundlsu

    So is Alex Capps shooting a pistol in that photo? With a vertical foregrip?

    • Patrick Mingle

      IIRC in that photo the SB15 was put on a registered SBR lower just to be safe

    • Registered SBR

    • As Alex and Patrick said it’s a registered SBR anyway and we talked about this before it ever was reviewed.

  • Bob Saget

    Unless that’s a registered SBR you just put the brace on for the picture, a vertical foregrip on a pistol is a felony.

    • Ed

      Unless the firearm is over 26″ long, then it’s just an “Other Weapon” if the barrel is less than 16″. Not “Any Other Weapon”, just “Other Weapon”. No tax stamp required and you can have a VFG. I don’t know if that muzzle device ( suppressor? ) can be included in the overall length or not.

      • Ed

        Clear as mud, and set in stone, right?

      • Suburban

        Muzzle devices don’t count toward overall length unless they are “permanently attached.” I put that in quotations marks, because silver solder is not technically permanent, and neither is welding, but both count as permanent according to the BATFE.

        • Cymond

          Interesting. What about bolt-on parts at the other end, like a rubber recoil pad?
          Can you provide any sources? I’m trying to figure it out (with proof) for my eventual SBR. Also, I want to get a 10/22 bullpup conversion kit, but am having trouble figuring out how to keep it over 26″ with a 16″ barrel.

      • Geodkyt

        Muzzle devices only count for barrel or overall length if PERMANENTLY attached (blind pinned, welded, high-temp silver solder, etc.)

    • It is an SBR.

    • Mickey R

      Not so fast there… ATF’s “opinion” is that a vertical foregrip makes a pistol an AOW. That doesn’t necessarily make it so. There has never been a final determination by a court on the matter, but I’m confident that ATF’s position would be rejected based on the letter of the law. For one thing, the legal definition of “Any Other Weapon” (26 U.S.C. § 5845(e)) specifically excludes a “pistol or revolver having a rifled bore” from being an AOW. Moreover, “pistol” is defined as (27 C.F.R. § 479.11): “a weapon originally designed, made, and intended to fire a projectile (bullet) from one or more barrels when held in one hand.” “Handgun” is defined as (18 U.S.C. § 921(a)(29)): “a firearm which has a short stock and is designed to be held and fired by the user of a single hand.” By adding a vertical grip to a pistol, one does NOT change the fact that it was “originally designed… to fire a projectile… when held in one hand.” Even under the definition of “handgun,” adding a vertical grip does not change that the “handgun” was “designed to be held and fired… [in] a single hand.” In fact, a federal magistrate judge held precisely that in U.S. v Davis: “Even after being modified with grips, the pistols are still ‘pistols’ as defined above and not ‘any other weapon’ as defined by 26 U.S.C. section 5845(e).” Problem is, ATF dismissed the AOW charge against Davis after the magistrate judge issued the report, thus there is no precedent on the matter.

      • Geodkyt

        The reason vertical foregrips on pistols are considered by current ATF thinking as transforming them into AOWs is because the stautory definition of a “pistol” or “revolver” includes the term “_A_grip at an angle to the axis of the bore” in the singular form. ATF’s position is that if Congress meant “grips”, plural, they should have said so.

        Since a pistol-sized gun with TWO grips isn’t (by that reasoning) a “pistol” or any other stautorily defined category, but it IS still concealable, it falls into the AOW category.

    • JLR84

      The vertical foregrip thing is still a gray area, but at the very least there’s an ATF determination letter stating that the Magpul AFG does not count. So you can toss that on your AR pistol with the SIG brace worry-free.

  • Spencer

    Ermahgerd! SBR ghost gun loopholez!

  • a

    If you take this letter at face value then it means you can mount a sig arm brace to a glock via an endo tactical stock adapter and use it “incorrectly” without sbr classification…

    • wetcorps

      But with the endo you can’t use the arm brace as an arm brace at all, only as a stock. What then?

      • a

        The sig arm brace has been clearly identified as a non-stock that does not change the classification of a weapon, so, legally, adding an arm brace to a firearm is no different from adding pink bows and ribbons to it. Or, more to the point, legally there’s no difference between adding an arm brace to an AR-15 pistol and adding an arm brace to a Glock pistol. As the letter clearly states, the ATF doesn’t recommend using any product incorrectly, but it doesn’t forbid it. Of course they sure might go and alter their stance if they saw you do it!

        • Geodkyt

          I’d still want a determination letter in hand confirming that specific point for a specific combination of relevant parts.
          Remember, an M4 14.5″ barrelled upper is wholly legal and non-NFA, so long as you have a pistol or registered SBR lower to mount to it (or no lower at all). But own a 20″ AR15 set up as a precision hunting rifle, decide to build an AR pistol, and receive the pistol upper before you have the pistol lower in possession, and that upper just magically transformed your hunting rifle into a Short Barrelled Rifle, even though you haven’t even let the parts touch.
          Same thing with a vertical foregrip — even OWNING one when you have a pistol it fits (and you don’t have a rifle, shotgun, machinegun, destructive device, or AOW it fits) makes that pistol an AOW.

    • No way I’d try that!

      • JT

        Send em’ a letter 🙂 I think though if you tilted the brace the right way it might work

    • Cymond

      I wouldn’t try it, but MAYBE with something that puts the “tube” higher than the grip, like the CAA Roni (or there’s another Glock conversion I can’t remember).

      • There are at least two other conversion kits kinda like the Roni.

      • Geodkyt

        I wouldn’t do it without an ATF determination letter saying it was OK (or using a Glock that has already been registered as an SBR), but DON’T jigger the tube higher — flip the arm brace upside down.

        • Cymond

          Yeah, I’m not about to fiddle with anything NFA-related without knowing exactly what is and is not legal. The recent rash of questions about the legal issues of polymer lowers makes me even more cautious than before when dealing with the ATF.

  • DougieR

    You can essentially use your pistol buffer to turn you gun into an SBR. 5.45x39mm was fine for years and now it’s banned because it’s now “armor piercing”. Your shotgun may suddenly have no “sporting” purpose according to a new study and public comment by ATF. And let’s not forget…don’t hang a pistol grip on the front of that pistol or shotgun or it becomes an AOW!
    The ATF…so much bullshit that if it didn’t already really exist, you couldn’t invent it if you tried!

    • The 5.45 isn’t banned the request to import are just on hold.

    • Cymond

      To further muddy the waters, ATF says the Magpul AFG is fine for use on pistols because it isn’t a vertical pistol grip. However, the law technically says an AOW is “designed to be fired with 2 hands” so that’s a bit odd (says nothing about the 2nd grip being vertical). And let’s not even get into the issue of “how close to vertical is considered not OK for a pistol”?

      • Who the heck knows. They have those that stay at about a 45 degree angle. Who’s on first?

        • gunslinger

          I don’t know. He’s on third and I don’t give a darn.

          • Lysenko

            Oh, that’s our shortstop

      • Eric S

        See Franklin Arms X0-26. To be an AOW it has to be concealable. So you can have a pistol with a foregrip if it is not deemed concealable, which is around 26in overall length. It’s just a firearm NOS at that point.

      • Geodkyt

        AOWs DO NOT have to be “designed to fire with 2 hands”. There are LOTS of AOWs that are designed to be fired with only one hand.
        The reason vertical foregrips on pistols are considered by current ATF thinking as transforming them into AOWs is because the stautory definition of a “pistol” or “revolver” includes the term “grip at an angle to teh axis of teh bore” in the singular form. ATF’s position is that if Congress meant “grips”, plural, they should have said so.
        Since a pistol-sized gun with TWO grips isn’t a pistol, but it IS still concealable, that means it’s an AOW.

        I don’t AGREE with the ATF reasoning on this matter, but it IS plausibly arguable enough to mean that it isn’t a (legally) “arbitrary” decision, necessarily. Which means that the courts will likely defer to ATF’s technical authority to rule as such. (Courts could still overrule ATF, as they did with “once a machinegun, always a machinegun” (Vollmer v. Higgens, 23 F.3d 448 (1994)) and converting a “pistol” or “revolver” to a “rifle” and back again without creating a “Short Barrelled Rifle” (US v. Thompson/Center Arms Co., 504 U.S. 505 (1992)). (Note that ATF has only quite recently admitted that US v. Thompson/Center Arms is actually binding on anything but the Thompson Contender.)

        • Cymond

          Yeah, AOWs are a confusing & diverse set of firearms. I know the 2-handed subject is complicated, but I need to read more about it. There are also the ‘smoothbore pistol’ AOWs & the ‘doesn’t look like a gun’ AOWs like the NAA wallet holster or a cane-gun.

          • Geodkyt

            Yup. AOW was intended to simply be a “catch-all” category to cover all concealable guns that couldn;t be neatly defined as handguns, rifles, or shotguns.
            Remember, the NFA originally was going to treat handguns the same as machineguns and silencers — and the SBR, SBS, and AOW categories were invented solely to ensure to “close the loophole” of people saying, “This ain’t a handgun — it’s a short rifle/wrist gun/etc.” NRA managed to get handguns stricken from the NFA during debate on the bill, but not the rest that were NFA solely because handguns were supposed to be covered as well.

      • nova3930

        Basically the underlying issue is that the ATF gets to make stuff up as they go, generally without even following the legal rule making process. Until congress steps in and puts a stop to it, we gun owners will forever be looking over our shoulder, wondering when the ATF will suddenly decide that what was perfectly legal yesterday, is now 100% illegal, go directly to jail for 10 years, do not pass go, do not collect $200, in fact pay Uncle Sam $250k….

        • Cymond

          Has there been prosecutions like that? I know when they reclassified the Street Sweeper as a DD, they allowed NFA registration (which sucks, but it’s not an arrest). And when they flopped on the Akins, I don’t think they arrested anyone, unless that person refused to comply going forward.
          ATF does a lot of shady stuff, but I have not heard of any arrests for ex post facto rulings.

    • 5.45x39mm 7n6 was banned because the fact that a commercially produced pistol was made available (even if not in any large numbers) in that caliber made 5.45x39mm a caliber useable in a handgun, under the law. By strict interpretation of teh law, if 5.45x39mm is a handgun caliber, then 7n6 is a round that uses an “armor piercing” bullet and is automatically banned by statute.
      ATF didn’t make anything up in the 7n6 decision — they applied the law, exactly as written. You could ask the Attorney General to exempt 7n6 as “sporting” ammunition, but given not just how the current AG feels about guns (it’s not “politics” to factually point out what his position is, without weighing in on the validity of it), but the inconvienient fact that 7n6 WAS designed for military use as a combat round, I doubt that appeal would go very far. . .

    • Porty1119

      5.45×39 is still okay. The issue is only with Russian-manufactured 7N6 steel-core rounds.

  • ValleyForge77

    Steve – I can’t thank you enough for sharing this. This question has arisen many times for me and it’s VERY helpful to get a document to reference. Thank you sir. I read TFB every day and it sure paid off today!

    • Thank you sir. I was really glad to see the letter because I’ve received a good number of email questions about these.
      I mentioned this above but I did learn you shouldn’t modify these braces. Specifically removing the elastic and velcro straps makes the thing an SBR then and there. Makes no sense but what does out of DC.

      • ValleyForge77

        Good call out. I had read that before as well. Can’t modify in any way. Thankfully Sig provides and extra velcro strap, just in case.

        • True enough. Century doesn’t supply an extra with their PAP pistol with a brace.

          • Cymond

            Is there a determination letter on the braced PAP pistol? It makes sense that it’s still a pistol, but then again, it’s a much more significant change than putting a SB-15 on a pistol that already has a buffer tube.

            If that’s OK, then it opens the door for other modifications. A brace could be added to a shotgun-type AOW to prevent classification as a SBS. Or a brace could be added to something like THIS to keep the length above 26″ and provide stability.

          • I haven’t personally seen it but I’m sure there is one. I happen to have a PAP with the brace on it I’m reviewing now. It’s pretty much a carbon copy of a Krink with the brace on it. It’s a very compact gun!

          • Alex

            It doesn’t need an extra determination letter, just like Slide Fire doesn’t need an extra determination letter for the 7 or 8 different platforms it works with. As long as the brace is attached to a “pistol style” buffer tube you are good to go.

  • guest

    So much jumping trough hoops… with the potential of serious prison time if SOMETHING is not in order.

    Just register as SBR and be done with it. What is the big deal? Is the tax stamp so wrong contra the possibility of doing something that MAY lead to serious trouble with the law?

    And btw, SBRs rock. All those pistols and almost-SBRs – not so much. Not at all in fact.

    • BOB

      What’s the big deal? Freedom.

      • Suburban

        Exactly, Bob dude.

    • GovtPudding

      But I can’t get NFA firearms in RI. This would be the closest I could get.

      • David

        I used to live in RI before I escaped a few months ago. I build a pistol with the brace for that specific reason – no NFA allowed in RI

    • BryanS

      Whats the big deal? $200 and a long wait for a stamp just to get approval to own legal items. And dute to that stamp, manufacture of those items is more expensive, and with economies of scale pointing towards a smaller market, prices go even higher, taking it out of the range of most people.

      Its a penalty for using equipment that they have no right to limit in the first place.

      • gunslinger

        some will say “shall not be infringed”

      • Leigh Rich

        BS: Some states do not allow SBR. So it is a big deal.

    • Cymond

      I just have a little to add to what others have said.

      First, SBRs are illegal in some states. I’m currently stuck in California.

      Second, SBRs require paperwork to cross state lines (and they all need to be NFA friendly).

      Third, most states* don’t allow a SBR to be carried loaded in the car, while a SB-15 AR pistol is just a pistol, and can be used for CCW in the car.

      *Supposedly, Pennsylvania’s only definition of ‘handgun’ is ‘a gun with a barrel less than 16 inches’ which means that SBRs and SBSs can be carried concealed with a standard CCW. (I am not a lawyer, this is not legal advice, etc.)

      • guest

        OK fair enough with the limits of some states.
        Then buy a bullpup like the Tavor!

        This is still better than lingering on the border of legality.

        No I am not making excuses for the inexcuseable (the limitations put on getting an SBR, legal status in states etc). Just saying that using a questionable way to mimic and SBR is IMHO not worth the risk.

        • Cymond

          A bullpup still can’t be carried like a pistol can be.
          Plus, IDK about other states, but CA requires semiauto rifles to be at least 30″ to avoid “assault weapon” status. Fortunately, that includes non-permanent muzzle attachments (I think) so there are a lot of bullpups in CA with fake silencers and really long flash hiders. It’s still small, but not as small as an AR-15 pistol with 10″ barrel.

  • BOB

    Good. I don’t really plan on buying the brace, but I do shoot my 300 BLK pistol with an A1 extension and cane tip, against my shoulder. I think its absolutely moronic to pay the ATF 200 bucks, open your life to The Man and wait a year to legally be allowed to pop 2 pins out and pop 2 pins back in.

  • OliverTabuger

    Haha beneficial to the community. You mean beneficial to Sig’s bank account.

  • To Tin Fung

    so.. if u use the arm brace, you can shoulder-fire an SBR legally?

    • You can shoulder an AR or AK pistol

      • a

        Where does the law make any distinction between AR or AK pistols and all other pistols? I’ve never seen anything to indicate that there’s any classification of that type at play.

        And no the arm brace doesn’t make it “legal to shoulder fire an sbr” since a pistol with an arm brace is still JUST a pistol and not an sbr

        • I don’t know that they do make a distinction between the two types. Anytime ATF puts out a letter it usually has a very narrow focus and never strays into another topic or question.

    • gunslinger

      sure, why not? because SBR can already be fired legally with the stock (by simple definition of an SBR)

      i don’t see any reason why you can’t fire a rifle w/o a stock (minus the 26″ OAL requirement)??

      • To Tin Fung

        no what I meant was, if you took a AR pistol, added the arm brace, then shooting it as an SBR legally without registering or paying the tax stamp.

        • ForTehNguyen

          no different than shouldering AR pistol buffer tube. Just ebcause you can put it to your shoulder doesnt mean it suddenly becomes and SBR. If I take a pistol and put it to my shoulder when I fire, its not an SBR

  • Jeff Smith

    Don’t hesitate to post anything from the legal side of the firearms community. This site has done a fantastic job of sticking to the facts.

    Keep up the good work!

    • Thank you Jeff—-

    • gunslinger

      I don’t see how posting the information regarding the legality of items is bad. where it would if TFB started pushing an agenda to either keep or change said reference..

      • Jeff Smith

        Sadly, many people can’t distinguish between “law” and “politics”.

        • M40

          I AM having a tough time making the distinction between law and politics. LAWS are made by elected congressional bodies and interpreted by the judiciary. The ATF is NEITHER, yet they are acting as an unconstitutional, extra-governmental ‘lawmaking body’… but that’s a whole other subject.

          Here’s the really confusing part. Typical liberal gun-grabber “logic” would seem to say that smaller and thus more concealable guns are somehow ‘bad’. Cutting down barrels or stocks to make a gun more concealable is ‘bad’ in their eyes. Okay… I don’t agree, but I get it.

          How then is it ‘bad’ if I take a pistol and ADD to it, whether with a big fat shoulder stock, a longer barrel, or extra grips? Wouldn’t this make the pistol somehow ‘better’ in the eyes of the gun-grabbing left?

          Adhering to the 20,000 odd gun LAWS already on the books is hard enough, but when you have a non-elected body making decrees, rulings and dictums on a daily basis, how is the average person supposed to stay within the law (whether REAL laws, or those made up on the spot by an ATF bureaucrat)?

          Or is the whole thing an absurd exercise to make legal gun ownership something akin to juggling slippery eels, while walking a tightrope, while people throw eggs at you?

          • gunslinger

            the thing is that by cutting down, you make it more concealable.
            however when adding to it, you are making it a more efficient baby killer, thus that is bad too. so it’s not that it’s concealable, it’s now able to fire more rounds from the hip accurately (as obsurd as it sounds) i mena, that’s why pistol grips are bad..they let you fire from the hip.

            just as absurd.

          • M40

            Hey, don’t knock the Hollywood, hip-firing, macho-man stereotype! Because of that persistent imagery, a lot of the yahoos we face in the middle east learned everything they know about shooting from watching dopey movies. I much prefer that our soldiers continue to face dopey, sterotypical numbskulls who can’t shoot straight. Thank you Hollywood for creating “hip-firing”!

          • Anon. E Maus

            Is that for real? Oh man, that made my day!

            Shit though, with these braces declared legal, people can make excellent HD carbines that are legally handguns, that’s brilliant!

          • pantsless_santa

            This is called “administrative law,” and it has been a mainstream (and essential) part of federal and state government since before WWII. To the extent Congress is capable of anything at all in the first place, it is just not equipped to legislate the minutiae of firearms regulations. Or environmental rules. Or car safety. Or securities regulation. Or crop insurance. Or NASA subcontracting procedure. Or prescription drug approval. Or timber sales. Or special ed. Or hydropower. Etc.

            Gun regulations have been around since the NFA and they will always be around. And, like all other federal regulations, they will be created by a federal agency, not by Congress. It’s legal, it’s normal, it’s the way things are done.

            And yes, your complaints are still reasonable.

  • ColaBox

    Damn that SSE looks great on that SBR.


    We truly live in a silly time.

  • Avery

    Has anyone produced a SPAS-style folding swivel hook for a buffer tube yet? If we’re going to go that route, might as well dust off a decent idea they used for bracing shotguns for one-handed use. And I’m talking the little folding end, not the whole stock.

  • Cymond

    Thank you for sharing this. This ruling makes sense, but it’s nice to have it on paper and know it’s official. And yes, there’s been a lot happening legally recently, but I’m glad you’re sharing it without diving into the political aspects. Just seeing it mentioned here lets us investigate the topics if we choose.

    But this raises more questions. Where do they draw the line?
    Altering a SB-15 may reclassify it as a stock. As Phil White mentioned in another comment, the SB-15 is only legal as long as it has the Velcro straps that let it function as a brace. And does the buffer tube matter? KAK Industries makes a buffer tube that increases the length-of-pull of the SB-15, but I have not seen a determination letter for it. Does a longer LOP alter the SB-15 too much and make it a stock?? Maybe a longer LOP shows intent to be fired from the shoulder. On the other hand, ATF has already stated in letters that it is legal to use an A1/A2 length buffer tube on a pistol, so LOP is arguably irrelevant.

    If the SB-15 is just an arm brace, then it should be allowed on any fiream, not just an AR pistol. However, if it is used on a fiream where it cannot function as a brace, we’re back to it potentially being considered a stock on a SBR.
    At least 1 other gun is already using an arm brace (Century PAP AK pistol, which I haven’t found a determination letter for yet, either). If an arm brace really can be used on any gun without being considered a stock, then it has more possibilities. Instead of a SBS ($200 stamp), you could buy an AOW ($5 stamp) with a SB-15. Also, AOWs are legal in California but SBS & SBR are not. I need to investigate the SB-15 in CA.
    As someone else mentioned, it may be useable on a Glock with conversion kit (where a stock would normally go).
    Or maybe you could put an arm brace on a pistol-grip-only shotgun, and cut the barrel down to 14″. It should be legal as long as it’s over 26″ ( That seems like a good option instead of a SBS, if this works.

    • The way this ATF letter reads I’d think you could add the stabilizing brace and cut down a shotgun to 14 inches. I’d darn sure want to find out for sure before I did it:-)

    • gunslinger

      it’s only official until either the law changes or the FTB changes their mind (which it may do)

      • Cymond

        You’re right that FTB may change their mind, but those cases are relatively uncommon, and it’s likely that they gave the SB-15 more consideration than an unknown product like the Akins (which the sample did not work). They clearly knew what they were approving in this case, although they may not have considered every possible application, such as my idea to use a SB-15 on a PGO shotgun discussed above.
        A change in the law is possible, but it would take even more time and have a higher chance of failure than an ATF reversal. It would also be highly publicized on all of the gun blogs & forums before being passed, so owners would have plenty of time to prepare.

  • Studenta ot Sofia

    I googled to see what is this brace about and…..on the SIG site
    there is a promo video. Suddenly I was surprised to see… that thing at 1:15-1:21 !!!!
    The video is also available here:

    Hint: it is also 0:24-0:26!!!!!!!

    • Studenta ot Sofia

      Do You see WHAT I see????

    • Studenta ot Sofia

      Hint 2: It is something with the weapon, but it isn’t about arb brace!!!!!
      Can’t believe nobody responded!

      • Studenta ot Sofia

        Sorry ment “arm brace”

      • Cymond

        The sling? What’s so special about it?? A Magpul? Maybe it’s a new Magpul model that wasn’t out yet when the video was released or something …
        I don’t see the big deal.

    • gunslinger

      a sling?

  • JT

    I think it’s pretty telling about a lot of people in the gun community. That despite clear evidence in the original ATF letter that the thing did not convert the AR pistol into an SBR, that it was not classified as a stock as it was, and that use does not create a different weapon out of an existing weapon, that people are so frightened of shadows that they spread FUD over this thing. It’s like we’re back in the 1990’s all over again when so much progress has been made. It’s like when the AW ban looked like it was going to put forth again and people were like “oh well, it was nice when it lasted.” No, this is a defeatist attitude and although a little caution is healthy, you’ve got the ATF right here telling you this thing is a brace and you don’t believe them, there are bigger issues

    • Cymond

      But the law also mentions the INTENT of the gun design. I can understand why some people would be concerned. If you design your AR pistol with a SB-15 with the intent to use it as a brace, then it’s a pistol. Arguably, if you design your AR-15 with a SB-15 with the intent to use it as a stock, then it’s arguably a SBR.

      There’s been a lot of debate on this issue by intelligent, knowledgeable people. Heck, I’ve even played “devil’s advocate” for both sides in the debates. It’s nice to finally have a letter to clarify things.

      18 U.S. Code § 921 A “(7) The term “rifle” means a weapon designed or redesigned, made or remade, and intended to be fired from the shoulder and designed or redesigned and made or remade to use the energy of an explosive to fire only a single projectile through a rifled bore for each single pull of the trigger. “

      • gunslinger

        THOUGHT CRIME!!!!

        Orwell and Tom Cruise will show up at your door!

      • JT

        lol. I was pretty angry when I posted as I sometimes am : ) That is something to think about, but I’m thinking, for the moment they’ve said it’s legal. They can obviously change their minds, but as it stood, it was not a stock. Good to keep wary that it could change, but no reason for someone keeping knowledgeable on gun issues to worry about it until they reclassify it. I think that’s a better way of saying what I was trying to say, although the skittishness and defeatism I do believe is widespread and I don’t like it, because I’ve seen it before.

  • Bob Esposito

    This is absurd… SBRs need to be taken off the NFA Title II list.

  • SafeArmsReview

    I recently discussed this very topic (SB15) in a recent video/blog.

    Seems like a lot of people tend to listen to jailhouse gun lawyers instead of doing actual research. With that said you can be doing everything to a “T” and all it takes is one corrupt officer/agency to take away all your stuff forever and there is often no recourse at times.

    The problem is why do we need the ATF meddling in citizen affairs anyway? Its not like criminals are ordering pistol to carbine conversion kits with after market mags & trigger assemblies. Criminals don’t care about laws – they get the cheapest stuff they can find. All gun laws do is make it harder for good people to defend themselves & exercise their 2nd Amendment rights IMHO. All this does is create more confusion.

    Consider the federal definition of a handgun…

    “Handgun” is defined under Federal law to mean, in part, a firearm which has a short stock and is designed to be held and fired by the use of a single hand… Gun Control Act of 1968, 18 U.S.C. § 921(a)(29).

    Then read this… “ATF has long held that by installing a vertical fore grip on a handgun, the handgun is no longer designed to be held and fired by the use of a single hand. Therefore, if individuals install a vertical fore grip on a handgun, they are “making” a firearm requiring registration with ATF’s NFA Branch. Making an unregistered “AOW” is punishable by a fine and 10 years’ imprisonment. Additionally, possession of an unregistered “AOW” is also punishable by fine and 10 years’ imprisonment.”


    So does that mean if I use two hands to shoot a handgun it means I’m breaking the law? See what I mean? However if I put a Magpul AFG on a pistol its legal even though it requires two hands to use it? How is it ‘making’ a firearm when I put on an accessory? I imagine some guys who’s wives spend thousands on ‘accessories’ need to fill out a form 1 and tax stamp; will it hamper the overspending? Probably not, so why even have such a reg? The more we try to regulate the more we put ourselves at the mercy of a corrupt officer/agent/agency.

    I imagine that with this recent Fort Hood shooting it will result in a resurgence of anti-gun legislation. Fact is its the gun free zones that are creating victims that cannot defend themselves and add to the carnage. It wasn’t until an armed MP showed up that the situation ended (threat turned the gun on himself). Question: How many lives would be saved if it was not a gun free zone?

    Oh well, it will only get worse before it gets better.


    P.S. I don’t mind legal posts because I know I am weak in certain areas and appreciate the sharing of info so I can more edumacated… edyucated… errr… smarter!


    • Cymond

      “So does that mean if I use two hands to shoot a handgun it means I’m breaking the law?”
      Handgun: “designed to be held and fired by the use of a single hand”
      keyword: designed.
      A handgun is designed to be held & fired in one hand. That design does not change if you choose to grip it with 2 hands instead.
      I do agree that the AFG ruling is weird. It’s apparently ok because it’s not a vertical grip. On the other hand, if a secondary horizontal grip was not OK, then pistols could not have any kind of handguard or barrel shroud, which does not seem to be the original intent of the NFA.

    • Mystick

      Remember, this is the same bunch that believes that somehow a pistol grip, threaded barrel, bayonet lug, or detachable magazine makes the gun “inherently evil” and anyone who owns one will inevitably show up at a school with crazy eyes and maniacal laughter to shoot up the place.

      • MichaelZWilliamson

        Which “Same bunch”? Ugly gun laws come from legislators, not ATF.

  • Ben Gurney

    Would this not be an AOW with the vertical foregrip though? (pic)

    • MenotYou

      You are correct.

    • Cymond

      Well, it actually says it is a SBR, not a pistol. At the time the picture was taken, the legal-to-shoulder status was not 100% set in stone.

      2nd, you can put a vertical forgrip on a “pistol” if the overall length is more than 26″. It’s technically a “firearm” but not a “pistol”. See the Franklin Armory XO-26 for details.

      Third, as I keep re-learning, the whole issue of putting a 2nd vertical grip on a handgun is gray area in the law. The law never says it’s illegal, that is ATF’s claim. Still, don’t violate it.

  • Some Rabbit

    An ATF determination letter is worth it’s weight in used toilet paper. It’s one dept’s opinion and subject to change whenever convenient without notice. Just a word of warning to buyers of bump stocks and trigger gizmos.

    In this case, being able to catch a violator in the act and proving it in court verges on the astronomically unlikely. Even if you caught it on video the shooter could say that he was just resting his cheek on the buffer but it wasn’t touching his shoulder…prove it beyond reasonable doubt.

    • MichaelZWilliamson

      FTB’s determinations are a little stronger than you seem to think.

      Most of the alleged “reversals” are from someone attempting to apply a letter for X to gun Y. In this case, I would not attempt to use this letter for an AK type pistol, only an AR type pistol.

  • Jeff N.

    If the brace isn’t considered a stock, by mounting it on an SBR didn’t you by the ATF’s rules manufacture an AOW since without a “stock” it can no longer be regarded a shoulder fired weapons per the ATF guidelines?-I think this just shows how their rules are draconian and backwards.

  • me ohmy

    yes… but a foregrip makes it an SBR.. doesnt it??
    if you rail a pistol and add a foregrip.. I think it does

    • Cymond

      No. First, it would be an AOW, not a SBR. Second, there is some conflict between the written law and ATF rules about adding a second grip so the legality is debated. Third, a firearm over 26″ is not necessarily a pistol, it could be just a “firearm” with no classification. See the Franklin Armory XO-26 and my other link.

      • gunslinger

        so because the XO-26 is longer than 26″ it’s not a rifle, because no shoulder fire. and not a pistol as it’s long. so it’s just a firearm? that’s how they put the forward grip on it?

        • Cymond

          Exactly. It defies any classification except “firearm” which I never realized was possible. There is precedent for this. West Hurley/Auto Ordnance produced a semi-auto Thompson “pistol” with 2 vertical grips. It was discontinued because of the 1994-2004 federal ban.

          It’s not a rifle or SBR (no stock), not a pistol (2 grips), and not an AOW (law says AOW is “concealable” and ATF says that 26″ is not concealable).

          PGO ‘shotguns’ like a Mossberg Cruiser are a similar case. ATF ruled a few years ago that they are not shotguns (no stock) so they can’t be sold to anyone under 21. This general “firearm” classification is why they don’t have a limit on barrel length, but they do need to stay over 26″ overall to avoid being an AOW.

  • Don from CT

    Hmm. He used a SBR lower. Well then he broke the law because he used a rifle lower in a pistol. Ha. In an attempt to be extra-careful, you broke the law.

    This is not a criticism of you. Its a criticism of the pointlessness and complexity of the law.


  • CavScout

    Every AR15 pistol thread on arfcom always spins out into a legal argument about the same things over and over. It’d be cool if a lot of the stuff got set in stone (for the better). Not sure why the braces seem to be the frosting on everyone’s pistol builds, especially on the cheaper ones. I’d put the extra $120 into the gun, optic, or ammo.

  • Adam Fluegeman

    Thanks for this. This has been known for some time among those who are well informed about ATF regs. But there are many more who are not. Hopefully those in law enforcement who are also into shooting can stay informed so they can avoid issues with a pistol mistaken for an sbr.

  • Derek Huffman

    These letters do not have the force of Law and are countermanded often. Ask Akins. Or recall that letter 5 or so years ago when the doofus at tech branch told some guy that engraving on an SBR was unnecessary. Oh, the blogs and boards lit up over that one. They weren’t nearly as diligent a few months later when another letter came out contradicting the first letter.

    • gunslinger

      as i recall with Mr. Akins… he submitted one version of his product (akin to the slide-fire) fitted for an SKS, which never worked at the ATF, but was given a go based upon design theory. then when he went into production with his 10/22 model, he incorporated a spring (thus making it different than the sks version) thus creating a MG.

  • Sabinerat

    it cant have a front pistol grip

  • Stomper

    Ya’ll do realize that the photo of the shooter above has a vertical fore grip (VFG) and is NOT legal on a pistol, right? The only reason the above is legal is BECAUSE it is on a registered SBR lower, so PLEASE do not think you can put the SB-15 arm brace on your pistol then in an unlimited fashion kit it out as shown in the above photo! The closest you can LEGALLY get is Magpul’s AFG on a pistol only rig.

  • some guy
  • Jev Adiah

    Now try handing the local gestapo the letter while they have their boot on your head. It looks like a stock, functions like a stock….guess what?

  • SNNN

    “Gun regulations have been around since the NFA and they will always be
    around. And, like all other federal regulations, they will be created by
    a federal agency, not by Congress. It’s legal, it’s normal, it’s the
    way things are done.

    …..and completely UNCONSTITUTIONAL. That we are now working, essentially outside

    the law is a reality here. Just because we think its OK….its not. I don’t see a “federal agency,” in my copy of the Constitution. If Congress is to lazy to do their job ,maybe

    they should resign so someone who does can replace then in the next election cycle.
    I realize this runs close to “politics” mods so delete if needed.