AR-15 Pistols – Clearing Up Some Misconceptions

The BATFE has been telling NFA applicants that their approvals could take as long as 15 months from the date their application enters the “pending” status. Those who have been through the process before know that it can take a few months to even get to the pending status. These new revelations coupled with recent gear developments have me reconsidering my stance on AR-15 pistols.

I wouldn’t say that I am anti-AR pistol and I also wouldn’t say that I think they are a great idea. I guess that I am somewhat agnostic toward them. However, what always bothered me was casual way that they were written off by many “experts” who sneered that they were toys without ever really backing that up with actual data. So, in an effort to find out what is really up with AR pistols, I am planning on building one and putting it through the wringer. I’ll report back with quantifiable data in regard to how they perform against a similarly configured rifle. That sort of project takes some time and while I have been preparing for it, I came across a lot of misinformation about AR-15 pistols that I would like to set straight in this article.

Photo courtesy of

Photo courtesy of

Before I get too deep into the weeds, I should say that am not a lawyer. This is not legal advice. You should also familiarize yourself with your local laws to ensure compliance. Understand that while many BATFE opinions are cited in this article, they are just that – opinions – which are apt to change.


The 4473 form that you complete at the point of purchase seems like a good place to start since it is where you AR pistol adventure will start. It is no longer necessary to have the lower transferred to you as a handgun. Receivers are now transferred as a “receiver.” This is stated directly on the current form 4473. You can build the receiver into whatever you like as long as it meets legal definitions of a handgun or rifle.

Cite: BATFE Form 4473

Once a Rifle, Always a Rifle

The BATFE has made it very clear that once a receiver is built into a rifle, whether by a factory or by you, it is always a rifle and converting it to a pistol is illegal. However, it is perfectly legal to build the receiver into a pistol first and then convert it to a rifle. If the receiver is built into a pistol first, you can configure it back and forth from handgun to rifle and back again as much as you want. However, you must be vigilant to ensure that a shorter than 16″ barrel is never on the receiver at the same time as a stock.

The proper order for converting an AR pistol to a rifle is to remove the short barrel (usually done by removing the entire upper receiver group), installed the 16″+ barrel (usually done by installing an entire upper receiver group), and then installing the stock. I repeat, the stock and short barrel must never be on the receiver at the same time or you will have created an illegal short barreled rifle (SBR).

The proper order for converting a rifle BACK to an AR pistol is to remove the stock, remove the 16″+ barrel, and finally install the <16″ barrel.

There is some wisdom in building every AR-15 lower receiver that you purchase into a pistol first. That way you have the maximum versatility should you want to convert it to a pistol later.

Cite: BATFE on converting pistols to rifles

Receiver Extensions

Speaking of removing and reinstalling the stock… One of the most widely spread gun-counter dogmas regarding AR pistols is that you must use a receiver extension (buffer tube) that cannot except a stock. People often cite “constructive intent” when discussing why you must use a receiver extension that can not accept a stock. They state that if you were to own both a stock and an AR pistol that could accept the stock, you could be cited for the intent to create an illegal SBR. This is not necessarily true.

Owning a buttstock is not illegal as long as you have a legal use for it. Installing it on an AR pistol to create an unregistered SBR is illegal. Owning a car that is capable of exceeding the speed limit is not illegal. Exceeding the speed limit is illegal.

In my opinion (for whatever it’s worth), a wise way to approach the situation is to say that if you only own an AR-15 pistol, don’t also own a buttstock. It will save you the temptation of installing it and prevent the appearance of illegal intent. If you own multiple other AR-15s that can legally accept a buttstock, feel free own as many buttstocks as you like. Just like if you own a legal SBR, you don’t have to register all your ARs as SBRs in order to own an upper with a short barrel.

“Constructive intent” is a boogeyman that has prevented a lot of people from doing perfectly legal things. Use common sense and follow the law as it is written. Using a standard receiver extension is legal and actually very handy if you plan on converting your AR pistol to rifle configuration as detailed above.

I do acknowledge that this is perhaps a gray area and even the cited letter below says that owning a stock with an AR pistol that can accept it “may” be breaking the law. So, without a doubt, the absolute safest way to go is with a receiver extension that cannot accept a stock.

Cite: BATFE on receiver extensions

Cite: More information here

Photo courtesy of

Photo courtesy of

Pistol Lowers Must Be Marked as Pistol Lowers

There was a time when having a pistol marked lower receiver made some sense but it has never really mattered what the lower says. It has always mattered how it was transferred. It is a pistol if…

  • It was transferred as a pistol (receivers are no longer transferred as pistols).
  • It was transferred as a receiver and then built into a pistol first.

Vertical Grips and Similar

Installing a vertical grip on an AR pistol is illegal. It, by classification, creates an illegal Any Other Weapon (AOW). However, recent BATFE clarifications have created some options you should be aware of.

The BATFE has clarified that it does not consider angled foregrips like the Magpul AFG a vertical grip and therefor it is legal to install on an AR pistol.

Additionally, if the AR pistol has an overall length of 26″ or greater (the BATFE’s definition of not easily concealed) and lacks a buttstock (not an SBR), you may install a vertical grip because it does not fit the BATFE’s definition of a “handgun”. AR pistols in this configuration do not fit any BATFE definition and thus are classed generically as a “firearm”. Guns that are classified as “firearms” may have vertical fore grips installed. To be clear, in this case the term “firearm” is an actual BATFE classification of a gun that meets certain criteria not a general term used for all guns.

The overall length is measure from the tip of the bare muzzle (the muzzle device does not count unless it is permanently attached) to the back of the receiver extension.

It should be noted that if you are carrying an AR pistol legally by virtue of a concealed handgun license, adding the vertical grip makes it something other than a handgun.

Cite: Franklin Armory compiled info on vertical grips

Cite: BATFE on AFG

Cane Tips and Buffer Tube Bumpers

The BATFE has clarified that a rubber cane tip placed on the receiver extension (buffer tube) does not constitute a stock. This can make the AR pistol easier to stand up in a safe and protect the rear of receiver extension.

Cite: BATFE on cane tips

Shooting an AR Pistol Certain Ways is Illegal

Some people will tell you that shooting an AR pistol with the receiver extension against your shoulder is illegal because the receiver extension then becomes a shoulder stock. That is incorrect. The AR pistol is a pistol by virtue of the way it was transferred, initially built, and the fact that its features meet the definition of a pistol set forth by the BATFE. Its classification can not be changed by shooting it a certain way.

This would be like saying that a 1911 or Glock become illegal if they are shot while pressed against your body. Again, use common sense and follow the laws as written.

Due to a recent reversal to the ATF’s position on the Sig SB15 Brace and the legality of using it against the shooter’s shoulder, this section may no longer be up to date. I am awaiting further clarification.

Wrap Up

AR-15 pistols don’t have to be complicated. Just do a little research, follow the laws as written, and enjoy yourself. If you are looking for more information, check out Haus of Guns’ ongoing coverage of what he is learning from his recent AR-15 pistol build. You can also check out’s recent build for some inspiration. Both sites offer good insight into what makes these guns work.

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20 Responses to AR-15 Pistols – Clearing Up Some Misconceptions

  1. Ben November 20, 2013 at 09:37 #

    Great writeup brother. Very nice job!

  2. Chris November 20, 2013 at 10:28 #

    About owning a butt stock with a pistol buffer tube that can accept a stock- If you own a full auto AR trigger, and own an AR, that is illegal whether the auto trigger is installed or not. If you own a lower receiver, and intend to build an SBR, you cannot legally own an upper with a >16″ barrel until you have the proper paperwork. I personally would not have a pistol lower that has a receiver extension that can accept a stock. And many firing ranges may turn you away as well.

    • Matt November 20, 2013 at 10:38 #

      I hear you and agree that what you are proposing could be a prudent way to approach things but the BATFE opinions, precedent, and the way that the legal system works (ie innocent until proven guilty) don’t necessarily back that up. It is not illegal to own a short barrel. It is illegal to install it, creating an unregistered SBR. The trigger argument is not necessarily comparable because the only full auto triggers that can drop into a regular receiver are auto sears which are a registered item themselves.

      The BATFE purposely uses open ended language like “it MAY be illegal to own a stock” because that is the prudent thing to do legally. However, if you own other carbines that can legally accept a stock there is no reason you can’t own spares. All that said, you can avoid any and all appearance of impropriety by just using a receiver extension that cannot accept a stock.

      This is exactly why I wrote the article. People are largely misinformed and far too willing to read things into the law that are simply not there.

      • Cymond April 9, 2014 at 08:42 #

        I do agree that so-called ‘constructive intent’ is often misunderstood and over-applied. However, it is a real thing. ATF tried to argue that a Thompson Contender kit (with short barrel, long barrel, rifle stock, and pistol grip) was a de facto SBR because it could be assembled into a SBR. The court struck that down because there was a legal purpose for every part, and only certain combinations were illegal. ATF will still arrest & charge your butt if you can’t find a legal purpose for every part in your possession.

        ” It is not illegal to own a short barrel. It is illegal to install it, creating an unregistered SBR.”

        It IS illegal to own a short barrel if you have no legal use for one. For example, if you only own 1 gun (AR-15 rifle with 16″ barrel), then it is illegal to also own a short-barreled upper, even if you have not installed it yet. You have no legal use for that barrel.

        On the other hand, if you own 1 pistol lower, then you can own as many uppers for it as you want.

        At a bare minimum, make sure you always have a legal purpose for every part.

  3. Spencer November 20, 2013 at 12:24 #

    As someone who is building his first AR this evening (it comes in this evening) the “there is some wisdom to building them all as pistols first” part may have helped a LOT.

    Thanks for the write up.

  4. yet another mike November 20, 2013 at 13:01 #

    The article has a link that purports to be “Cite: BATFE on AFG” but it appears to go to an image that does not actually reference AFGs in any way.

    • Matt November 20, 2013 at 13:16 #

      Thanks Mike. I was juggling too many cites! It has been corrected.

  5. Ebbs November 20, 2013 at 15:56 #

    I agree with Ben and company! Well done with cited resources and all. We’re going to break this thing wide open. I’m already starting on another pistol!!!

  6. rob November 20, 2013 at 19:30 #

    Thanks for a very educational article. I appreciate you citing your sources as well. It helps prove your ethos. Good Job

  7. Jim November 20, 2013 at 19:43 #

    If you are building your own AR, how does it matter if you build a pistol or rifle first. No one knows what I built.

    • Matt November 20, 2013 at 19:45 #

      Good question Jim. I didn’t say it made sense. I just follow the laws as written.

  8. David343 November 21, 2013 at 07:32 #

    Good write up, it shows how truly ridiculous the BATF is. My ARpistol (bought and transferred as such as such) is a great runner out to 200 meters. It is an excellent MOUT training tool.

  9. BYoung February 6, 2014 at 21:57 #

    I don’t understand this wording:
    “Additionally, if the AR pistol has an overall length of 26″ or greater, you may install a vertical grip at which point it ceases to be “handgun” by definition and becomes a “firearm” by definition (it reverts back to a “handgun” when the vertical grip is removed)..”
    If it’s over 26″ inches it’s not a pistol anymore so what does adding a forward vertical grip do? You can’t make it a rifle or pistol by adding or removing a forward vertical grip.
    If it’s under 26″ no vertical grip allowed=it’s a pistol
    If it’s over 26″ it’s a rifle=vertical grip allowed

    • Matt February 6, 2014 at 22:08 #

      That is incorrect. If it has a barrel that is less than 16″ long and a 26″ or greater overall length, it becomes a “firearm” by definition when you add a vertical grip. It is not a rifle because the barrel is still less than 16″ in length. It is still a pistol right up until the point that the vertical grip is added at which point it becomes a firearm which is a sort weird limbo in which several guns that don’t quite meet other definitions sit.

      It may all seem nonsensical and I suppose it is. I really highlights how insane gun laws have become.

  10. Nick March 18, 2014 at 15:26 #

    Wouldn’t adding the forward grip to the pistol ar (regardless of length) make it an AOW, which is required to be NFA registered? My understanding was that a pistol with a forward grip constitutes an AOW. The nfa tax on these is negligible, but still… it’d be a felony to do so without the proper paperwork.

    • Matt March 18, 2014 at 22:25 #

      That would make more sense than the actual rulings but the cites are listed that include letters direct from the BATFE that support exactly what I wrote – you can ad a vert grip if the overall length is 26″ or greater.

    • Cymond April 9, 2014 at 08:48 #

      I’ve explained this many times recently, and I’m worn out, so I’ll just provide sources to look in to.

      First, see the Franklin Armory XO-26. Then see the Thompson 1927A5 “pistol”.

      XO-26 description:
      no shoulder stock (doesn’t meet the definition of a a rifle or SBR)
      11.5″ barrel (doesn’t meet the definition of a rifle)
      vertical foregrip (doesn’t meet the definition of a pistol)
      26.5″ long (not “readily concealable” under the NFA so not an AOW)

      How would this be classified? It is a firearm, but it defies classification under any technical definition.

  11. Jeremy W April 9, 2014 at 00:25 #

    I say When you first build it take pictures what show date/serial number showing it as a pistol. Even if the pistol upper is on it for 5 mins you will have a better chance at showing its a pistol first. Also hopefully the Paper work from your FFL will show it as a lower only or pistol.

  12. Joe Nosseb April 20, 2014 at 22:41 #

    OMG, not a single person saying how absolutely ridiculous this whole argument is? WTF, a gun is a gun is a gun. I don’t care if you have a .40 cal shovel or a 40mm shovel, it’s still JUST A SHOVEL! So buy, build, make whatever-the-hell you want and assert your bloody rights as a human being. Nobody, and I mean NOBODY, has the right to tell you what to do (except your spouse 🙂


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