AR-15 and pistol. The two words don’t exactly sound like they would mix. How would a dedicated rifle platform become a pistol? As strange as it sounds, a simple google search reveals we can buy an AR-15 pistol today via gun store or the internet shipped to an FFL. AR-15 pistols are often much smaller than standard AR-15 rifles, with short barrels, most commonly the shortest are 7.5 for .223/5.56. An AR-15 in 9mm can come with something as short as a 4-inch barrel, though.
Defining the AR-15 Pistol
An AR-15 pistol is a weapon that has a barrel shorter than 16 inches, does not have a stock, and is shorter than 26 inches overall. The lack of a stock defines the AR-15 pistol as a pistol. If you equip an AR-15 platform of any caliber with a barrel shorter than 16 inches and a stock, it becomes a short-barreled rifle. A short-barreled rifle is legal to own in most states, but requires the user to go through the NFA process, register the weapon, and pay a $200 tax stamp.
An AR-15 pistol allows the user to have a barrel shorter than 16 inches, without having to go through the NFA process. Some states will prohibit the ownership of short-barreled rifles regardless of the federal law. This makes an AR-15 pistol the only option for someone wanting a short barrel AR-15.
Although the standard AR-15 pistol fires a rifle round and feeds from rifles magazines, it is still pistol-based on the ATF’s definition of a pistol. So even though it delivers rifle performance, its lack of a stock, its short barrel, and overall length, makes it a pistol.
Building an AR-15 Pistol
You need to start fresh. You’ll need a lower receiver. AR-15 lower receiver manufacturers do not label their receivers pistol or rifle anymore. A receiver is sold as a receiver, not specifically as a pistol or rifle, so you can purchase any receiver to turn it into a pistol. If you are interested in using an 80% lower receiver you are welcome too.
Building an AR-15 pistol is often the exact same as building a rifle. There are a few key differences. You must use a pistol buffer tube and a pistol buffer. A pistol buffer tube does not allow the user to attach a stock, however, if you choose to use a cheek rest, you’ll use a keyed buffer tube. If you build your own upper receiver, you will need a pistol length gas system. That is where the main difference between building a pistol and a rifle end.
When building an AR-15 pistol, you cannot convert a rifle into a pistol. So you cannot take your existing rifle and turn it into a pistol. However, after you build your AR pistol, you can later convert that into a rifle, and then back to a pistol legally.
You cannot add a stock, but you can add a variety of accessories to make the weapon easier to shoot. You can equip a Thordsen cheek rest to, you guessed it, rest your cheek and use proper sights. You can also equip a SIG Tac Arm brace or a KAK Shockwave brace that you use to brace the weapon on your arm or use as a cheek rest. You cannot shoulder any of these items or the weapon becomes a short-barreled rifle according to the ATF.
You cannot equip your weapon with a vertical foregrip if it is a pistol. You can, however, use an angled foregrip. The Magpul Angled Foregrip is completely legal to use on a pistol and can greatly increase the control you have over the weapon.
If you only own an AR pistol, it may be prudent not to own any AR-15 stocks. Even if it is never equipped on the weapon, you may find yourself in hot water due to something called constructive possession. However, if you already own an AR rifle, or even a 16-inch upper receiver, you have a legitimate reason to own a stock.
Some states restrict your ability to carry a weapon with a concealed carry permit to a pistol. This includes how you carry the weapon in a vehicle. When you possess an AR-15 pistol, it does allow the user to store it as a pistol in their vehicle. Many prefer a larger platform to deal with more serious situations.
Lastly, AR-15 pistols can be a ton of fun. They create a vivid fireball when fired, a heckuva noise, and they are smaller and lighter than their rifle counterparts. They are easier to maneuver, and allow you to create a unique weapon. Staying legal is easy and if ever in doubt, you can actually write the ATF for clarification on one accessory or another.