Fielding some questions about AR-15 pistols


With the publication for comment of the ATF’s proposed new restrictions on AR-15 pistols, a number of readers have contacted me, asking what they can do to prepare for the new regulations.  There are several practical steps one can take, and of course they all depend on whether or not the regulations are implemented as currently drafted.  They also depend on whether or not legal challenges to those regulations are successful, something we probably won’t know for years as they wend their way through the court system.  Nevertheless, in order to prepare ourselves for what’s likely to be our new regulatory reality, at least for a time, let’s look at what can be done.

First of all, the ATF proposes that so-called “wrist braces” that are no more than a fig-leaf for a pseudo-stock should be banned.  This encompasses most of the products out there.  Let’s face it, from a strictly legal standpoint, the ATF is correct here.  Most pistol braces are intended to be used from the shoulder, no matter what their manufacturers may pretend.  Therefore, we should be ready to remove the wrist braces from our pistols.  Fortunately, this isn’t hard to do.

I’d suggest also replacing the six-position carbine buffer tube, like this one, with a pistol buffer tube like this one, which offers no adjustable stock capability.  The mere ownership of an AR-15 pistol with a multi-position buffer tube, plus a spare stock of almost any type (particularly a rifle or carbine stock), might lead the ATF to invoke the legal doctrine of “constructive possession“.  In other words, they’d presume that we intended to put the two items together and make an illegal short-barreled rifle (SBR).  The courts have ruled that this is, indeed, a thing, so the onus would be on us to prove that we didn’t have that intention and had never done it.  It’s hard to do that.  Ergo – make the problem go away before it becomes a problem.

I haven’t found any problem shooting an AR-15 pistol with a smooth buffer tube from any position, including my shoulder.  I’ve seen some shooters who’ve fabricated rough-and-ready shoulder pieces from pipe insulation tubing, slipping it over the buffer tube and closing the slit with black duct tape.  They can take it off the buffer tube and throw it away at a moment’s notice if necessary.  Since it doesn’t look anything like a shoulder stock or arm brace, it’s unlikely to be identified as such if it’s separate from the weapon.  I’m not advocating you do that, you understand – I’m just mentioning what I’ve seen others do.  There’s also the option of wearing some sort of shoulder padding, which isn’t mounted to the gun at all and therefore breaks no laws, rules or regulations.  Well-known devices such as a PAST recoil pad are probably not thick enough to give enough clearance from the shoulder to sight along a short buffer tube.  However, if the pad was make thicker by inserting something behind it, like a second or third layer of foam padding, it would probably work fine.

The next issue is the overall length of the pistol.  The ATF wants to decree that it should be no longer than 26″ from the tip of the barrel to the rear of the buffer tube.  That’s not very long.  In fact, allowing for the standard dimensions of upper and lower receiver and buffer tube, it leaves only about 7.5″ for the barrel.  A barrel that short in 5.56x45mm, the standard AR-15 chambering, isn’t long enough to allow all the propellant in the cartridge to be burned before the bullet leaves the barrel.  That results in horrendous muzzle blast and relatively inefficient ballistics, compared to a bullet fired from a longer barrel.  Cartridges such as the 300 AAC Blackout or the time-honored Russian 7.62x39mm are not affected as much by a short barrel, but will still lose some performance.

(I do suggest that you re-barrel your AR-15 pistol(s) with 7.5″ or shorter barrels, which are relatively easy to come by.  I’m doing this as a matter of course, because I don’t want to end up in jail by defying the authorities.  Others are more inclined to be defiant.  That’s your choice . . . but be aware that if you need to use that weapon for self-defense, and the authorities subsequently find out that it was in an illegal configuration, you may face federal firearms charges even if your use of that weapon was entirely legal.  That’s not a good place to be.)

At any rate, once you’ve re-barreled them, choose ammunition that’s optimized to work well out of shorter barrels.  See last year’s discussion of various cartridges for more information.  Briefly, for defensive purposes out of such short barrels I’ll use the FBI’s FBIT3 load or an equivalent in 5.56, the plastic-point Hornady 123gr. SST round in 7.62×39, and heavy soft- and hollow-point loads in 300 AAC Blackout.  Also, don’t expect such a short barrel to give you good performance or great accuracy at longer ranges.  For practical purposes, I’ll consider a 7.5″ AR-15 pistol to be a 100-yard gun, with possible utility out to 150 yards, but dubious ballistic efficiency that far out.  YMMV, of course.

The other solution, if your present AR-15 pistol barrel is 11.5″ or longer, is to extend it to 16″ or longer (the minimum legal length for a carbine barrel) by pinning and welding a long flash-hider or other extension on it, such as the XM-177 style that was popular on Colt short-barreled carbines during the Vietnam war.  Some versions aren’t legal, because the ATF regards them as suppressors, but others are.  There are many variations on the theme.  I’ve tried this one and this one, and like them.  Being pinned and welded, they’re regarded as permanent fixtures, and therefore become part of the overall barrel length.  If you don’t pin and weld it, they’re temporary, and therefore not part of the overall barrel length.  Be warned!  The ATF has no sense of humor about this!

Another factor to consider is the use of a folding stock adapter (such as this one) on an AR-15 pistol.  Many shooters have them, including myself.  I like the way they allow the weapon to be folded into a very short length.  It can be dropped into even a small backpack or duffel bag for easy concealment.  However, the problem is that such adapters add between one and one-and-a-half inches to the overall length of the firearm when in the unfolded position.  That might mean that your AR-15 pistol would exceed the 26″ length limit – a non-starter.  You’ll have to carefully measure how much leeway you have to work with, and plan accordingly.  One man I know has put a 6″ barrel on his AR-15 pistol to allow for that.  I think he’s sacrificing an awful lot of ballistic performance, but that’s his choice.  Personally, with an already short AR-15 pistol, I’d rather do without the folding stock adapter.  I’ll simply separate the upper and lower receivers, and carry the weapon like that.  It’s a matter of a few seconds to mate them together, drive home the pins, and have a working firearm again.

What about sights?  The ATF proposes a point system to determine whether an AR-15 pistol is intended to be fired from the shoulder.  Out of a 4-point maximum, they’ll allocate 1 point for iron sights on the pistol, and 2 points for a red dot sight.  To me, this is nonsensical.  If you don’t have sights on the weapon, how can you aim it accurately, whether fired from the hand or from the shoulder?  I think this part of the proposed regulations will be very susceptible to court challenges, and I’ll gladly join such actions myself, because the proposed rule threatens to make the weapon unusable.  In the meantime, I’ll make sure any red dot sight I may use is pocket-size, and has a quick-detach mounting system!

Finally, a critically important point.



Remember what we said about “constructive possession” above?  The ATF might argue in court that since you have an AR-15, but don’t have it in pistol configuration and/or don’t have an SBR registration for it, then the mere possession of a barrel or receiver group that fits SBR criteria implies that you intended to (or had already) fitted it to your weapon.  For example, a 10.5″ barrel, mated to a standard AR-15 pistol configuration, will make the weapon too long for the 26″ criterion the ATF uses – so it will no longer be considered a pistol.  However, it’s also too short to be considered a rifle or carbine, which require a minimum 16″ barrel length.  Ergo – you are in “constructive possession” of an SBR, whether you like it or not.

You don’t want to land yourself in that much legal hot water.  Trust me on this!  If you intend to retain such an intermediate-length barrel and/or upper receiver group, or more than one of them, register one or more of your lower receivers as an SBR, despite the expense.  That way, if an ATF agent starts asking questions, you can legally fit that intermediate-length barrel to your SBR (even multiple receivers and/or barrels), so your possession of it is legal.

Stay legal, and you’ll stay out of jail.  Disobey the law at your own risk, particularly if you use your “illegal” weapon in any situation that brings it and/or you to the attention of federal law enforcement.

Choose wisely.



  1. There is absolutely NO firearm that is "unlawful" or "illegal" in the possession of any US citizen… It is the fake bullshit laws that are ILLEGAL….. Come to my house to mess with me about any firearm you think I may have, you leave at gunpoint or die…

  2. You can not put a longer barrel on and be legal. Once a lower is used as a pistol lower it cannot become a rifle lower.

  3. @Mountain Rat: Sorry, but you're wrong. It's the other way round. You can't make a rifle lower receiver into a pistol by fitting a shorter barrel, but you can convert a pistol lower receiver into a rifle by putting a longer barrel on it. However, once you've done that, the lower receiver is regarded as forever a rifle – you can't re-convert it back to a pistol.

    Crazy, yes, but them's the regulations. No-one ever said they had to be logical. (Witness debit points for the sights one uses on one's pistol, when the pistol is actually useless without sights!)


  4. I hope you are correct on this. I will have to do some more research on this. I have an excellent Daniel Defense AR pistol and push comes to shove I would rather convert to a rifle than have to get rid of it all together.

  5. Good advice all Peter. One of life's realities is that if someone sees one of your firearms then they're likely to tell someone else about it. Being subjected to a search warrant for firearms or found with one in noncompliance on a range leaves you open to a seizure and or arrest. Eiter option is to be avoided if at all possible.

    If someone's running a brace in order to avoid paying to register an SBR then why not just go ahead and register it as such? Set up a trust and go ahead and buy yourself a suppressor or a short barrel shotgun at the same time? Then one trust is taken care of at the same time?

  6. I have an AR-9 9mm pistol with a 10.5" barrel and a Tailhook brace. I had to mill down a carbine buffer tube to get the 1st gen Tailhook to fit. Removing the Tailhook is easy but the 10.5" barrel is what gets me on the 26" max length. As is, it is 26.75".

    I will look into a pistol length buffer tube to see if it is shorter. If not I will take tube and cut an inch off the end to shorten the tube and weld it up. I am running a spacer in the carbine tube so this would fix my issues.

    A far as paying to register it as a SBR why would I want to register any of my guns for any reason. Yes I obtained all of them legally and none were 80% chunks.

    +1 Axeanda45

  7. Sorry Peter, but a lot of this advice is incorrect.

    The "Constructive possession" of a SBR issue was dealt with in United States v. Thompson-Center Arms Co. (1992).

    T/C sold a kit with a pistol frame with short 10" barrels and a long 16"+ barrel with a actual shoulder stock.

    A pistol can have a long 16" barrel and then an actual stock attached and removed, it's still a pistol.

    Also a firearm that is over 26" with a barrel of less than 18" or 16" that doesn't have a shoulder stock is not a pistol, rifle, or shotgun and is legally just a "firearm". There are several of them, the most popular is the shockwave griped ones that fire shotgun shells.

    This is way they have a little line at the top of the page saying that it doesn't apply if it's over 26".

    So everyone just calm down and don't do anything hasty.

  8. I think Ratus may have it right… assuming the laws (and Supreme Court rulings) apply. It'd be fun watching (preferably not from the dock!) government lawyers try to explain how putting a longer barrel on a legal pistol (even one with no shoulderable feature) could turn it into an illegal short-barreled rifle.
    "Alexa, what does 'arbitrary and capricious' mean?"

    BTW, according to the CAD model I'm looking at, the distance from the front of the buffer tube to the breech is right at 7", so if a pistol-type buffer tube is 7.25" (per that Midway product listing), that leaves 11.75" for barrel plus muzzle device, so a 10.5" barrel with just a thread protector installed should bring the total in under 26", I think. The weight-as-configured limit is another matter, and the CAD model doesn't tell me about that.

  9. "Alexa, what does 'arbitrary and capricious' mean?"

    So MUCH Said in this off hand comment. We allow NAY PAY for the surveillance states devices like cellphones, Siri, Alexa, and smart devices like freaking Refrigerators AND then COMPLAIN about Intrusions….

    Arbitrary and Capricious is when your shot to bits by a line of black clad troopers over something you would ARGUE was LEGAL and or Permitted by the Constitution and it's Amendments.

    Sure guys, lets dance at the edge of the flaming volcano will we? After all it's our RIGHTS eh?

    Go on chatter about your toys like the 1st Amendment (Freedom of Speech) and 2nd Amendment (armed militia) and the Fourth Amendment: Protects against unreasonable searches and seizures by the government. ALSO 5th Amendment Freedom TO BE SILENT as not to self condemn like maybe ON THIS LIST?) STILL have legal Power.

    The Electronic Python LOVES YA ALL. You keep it well FED.

    "Alexa, what does 'arbitrary and capricious' mean?"

    It means the Criminals in DC and your local state governments are writing and re-writing and IGNORING Laws as they SEE FIT to enable their goals.

    WE are the Law abiding Citizens, Criminals care not a whit about gun laws or any laws per say. AND they are USING LAWFARE like a club on us baby harp seals.

    Over at American Thinker an recent article "Are we Nazi Germany" needs to be read and thought about.

    They cannot force us into the box cars unless we surrender. The Good Citizens of Germany WILLINGLY Surrendered their firearms for "The Good Of the State and to REDUCE Crime".

    Better KNOW who you can trust with your life because that IS That serious.

  10. all this will be moot if biden's gun plan is enacted. assuming we obey it that is. in the meantime, i will add a long fs to one, a short buffer to another, covert the rest to carbines. i like that folding gizmo tho, may have to get one or more.

  11. The length of the barrel isn't what makes it a rifle – the *stock* is. Put a stock on a pistol, in the eyes of the ATF it is now and forevermore a rifle. (Speaking of capricious and stupid.) Same goes for AOW and "other" shotgun-based firearms – stock? Congratulations on your SBS.

    And the whole magillah in question is ATF redefining braces as stocks, essentially. (See "capricious and stupid" above.)

    The T/C decision is specific to that particular weapon/system – it doesn't cover everything, just the intended configuration of specific barrel length *and stock*. Still have to have the 16" barrel attached before the stock, but the courts found that it wasn't *intended* to be used in an SBR configuration.

    Back In Tha Day, there were a helluva lot of military handguns that had attachable shoulder stocks, because of wishful thinking as to how useful these would actually be. And many of them got the stock attachment part butchered off or otherwise made useless, because of the immense danger of illegal SBRs. (Capricious, stupid *and* wishful thinking – hat trick!)

    Even more on that: any surplus handgun that *does* have functional stock attachment hardware, *can* use a stock without being an SBR (under Federal law) – *as long as it's a period stock*. A number of years back, someone in one forum I lurk in was getting jammed up because his legit original C&R handgun (Mauser or Ingliss High Power, I forget which) had been sold to him with a repro stock. (That may have changed at come point – I stopped following such news because the Chinese .45 Broomhandles went from $spendy to $Texas and are currently approaching $Near-Earth Orbit.)

    Personally, I'm skipping the entire brace issue by going full SBR on my two shorty builds. Since flamethrowers aren't regulated yet, the 7.5" 5.56 barrel will be extra-obnoxious with the repro duckbill or the even-older-school conical flash hider.

    Disclaimer: IANAL, puppy-popper, or have a dog in this hunt other than wanting people not to get jammed up because of misunderstanding where the ATF magic transforms from "OK" to "EXTERMINATUS!".

    Also, I really with Washington State allowed SBS, because I have a crappy cheap Chinese Ithaca 37 clone that really wants to be cut back to the front mag support…

  12. Oh, I missed one point – a rifle lower, either by virtue to having been stocked at some point, or marked/registered as a rifle, *cannot* legally be made into a pistol. A lower marked/registered as "pistol" or "other" may be used. More ATF yivshish…

  13. Anything coming out of BATF-E is bullshit, as is the NFA altogether. Unfortunately, that does not reduce your danger from these petty tyrants, so let's face facts – the checklist of "pistol" features is simple misdirection, since they included that little blurb about how EVEN IF IT STAYS INSIDE THEIR POINT SYSTEM, THEY CAN DEEM IT AN SBR, ANYWAY. F-Troop is not offering any way out of paying the tax, hell they want ANY AR/AK variant restricted and taxed, if not banned outright. Why play their game? Hell, I'm in Md., where I CANT BUY detachable magazines larger than 10 rounds, no possession ban, yet… but there are "magazine repair kits" that can be mailed to me, that assemble into standard capacity units. 🙃 I'm going to build a rifle, a pistol, and if push came to shove I'll teach how to make Phillipino shotguns to folks, so arms can be otained from tyrant forces. HOARD AMMO, PEOPLE. Devices to use it can be cobbled together from Home Depot's plumbing section. Are they going to outlaw machine tools? Guns are simple devices to make, a Sten gun is civil war era plumbing technology, other than the cartridge cases… I'll build a 16"-18" barreled AR, they'll never know about it, since I'm not a criminal other than to a tyrant.
    Rant mode off….

  14. Peter, You and I seem to be reading things a bit differently.
    I agree that a 26” firearm with a brace would be an automatically considered an SBR under these rules. I can’t see where a 26” firearm with a pistol tube and no brace (installed or under the control of the firearm owner) would be considered an SBR. The worksheet seems to indicate that it is simply not suitable for use as a braced pistol rather than not a pistol period. The ATF even offers instructions to remove the brace in order to comply (as the first option)

    That said, I understand and appreciate the abundance of caution. Weasels gonna weasel and they’ll try to twist this whatever way they can to get you.

    I’m just not reading it where it calls an unbraced 26” AR an SBR.

  15. @Engineering Johnson: Zeke! Nice to hear from you!

    You're right that technically (I say again, technically) a 26" AR pistol with no brace isn't an SBR. However, the new regulations include a "weasel clause" that says the ATF can nevertheless classify any AR pistol as an SBR if, in the ATF's discretion, they think that's what it is. So, even if you comply with the letter of the rules and regulations, if you don't get on with the examiner . . . you're still screwed.

    That's why I advise an abundance of caution. You aren't dealing with a clear, unambiguous legal standard, but one where personal judgment and discretion can override common sense. This does not make me happy, but we're stuck with it – at least for now.

  16. Yep, yep, and yep. The weasel clause can make even a 4” barrel pistol into an SBR. At this point I figure they’re going to call any AR under a 16” barrel an SBR and anything over the mark a machine gun or some other such nonsense.

    It is indeed a no win situation

    Also, we need to catch up!

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