AR-15 Pistols

What Is an ARP Gun? AR Pistol vs. AR-15 Rifle

An AR pistol — commonly called an ARP gun or ARP pistol — is an AR-15 pattern firearm with a barrel under 16” that is legally classified as a pistol rather than a rifle or short-barrel rifle. The key distinction: a pistol-braced AR has no rifle stock and no NFA classification, meaning no $200 tax stamp and no suppressor wait. The brace replicates the shoulderable feel of a stock while maintaining the pistol legal classification. For buyers who want a compact AR platform without the NFA process, the AR pistol delivers it. Since January 1, 2026, the $200 NFA tax stamp has been eliminated entirely, making short-barrel rifles and suppressors more accessible than ever — but AR pistols remain a clean, simple option requiring no additional paperwork beyond a standard firearms purchase.

Caliber Selection: 5.56, .300 Blackout, 9mm, and More

AR pistols are available in the full range of AR-compatible calibers. 5.56 NATO is the standard choice — the widest ammunition selection, the most parts availability, and the flattest trajectory. .300 Blackout is the premier suppressor-optimized caliber — subsonic loads with a quality can produce genuinely hearing-safe report, and supersonic loads provide serious terminal performance. 9mm AR pistols use Glock or Colt-pattern magazines and share caliber with your carry pistol, simplifying logistics. 7.62x39mm provides AK ballistics in an AR platform for buyers who want the caliber in a familiar manual of arms. See our .300 Blackout ammo page and .223/5.56 ammo page for ammunition selection.

Barrel Length: Choosing Your Configuration

AR pistol barrel lengths typically run from 7.5” to 11.5”. Shorter barrels (7.5”–8.5”) produce the most compact overall package and are optimized for close-quarters use — velocity loss is significant in 5.56 but manageable in .300 Blackout where short barrels still produce adequate pressure for reliable cycling. Mid-length barrels (10.5”–11.5”) balance compactness with improved velocity and are the most versatile all-around AR pistol configuration. For suppressor use, longer barrels give the can more distance from the shooter’s face and produce better sound reduction. Pair your barrel length choice with caliber selection for the right combination.

Draco and AK Pistols: The ARP Alternative

The term “ARP gun” is also used informally to refer to AK-pattern pistols like the Century Draco and Micro Draco. These 7.62x39mm pistols share the same legal classification as AR pistols and bring AK reliability and the proven 7.62x39mm cartridge to the pistol format. For buyers who prefer AK ergonomics and the 7.62x39 cartridge over the AR platform, the Draco family is the most popular AK pistol option by a wide margin. See the Draco pistol page for full configuration details.

Suppressors and AR Pistols: The Perfect Pairing

AR pistols are the most popular suppressor hosts in the civilian market. The .300 Blackout chambering was specifically designed for suppressed use — subsonic 220-grain loads through a quality suppressor produce hearing-safe report without a hearing protection requirement. 9mm AR pistols are similarly well-suited to suppressed use. Since January 1, 2026, the NFA $200 tax stamp has been eliminated, making suppressor ownership straightforward. See our suppressors page and .300 Blackout page for suppressor-optimized AR pistol pairings.

SBR Registration via ATF eForms

If you want to add a full buttstock to a short-barreled AR pistol and register it as an SBR, the process runs through the ATF eForms system using a Form 1 (Application to Make). Since January 1, 2026, the $200 NFA tax stamp has been eliminated — SBR registration is now free. You file the Form 1 before making the modification, receive ATF approval, then add the stock. Impact Guns can assist with the process at our Ogden and Boise locations. For a complete guide to the eForms system including Form 1 and Form 4 transfers, see our ATF eForms guide.

Frequently Asked Questions: AR-15 Pistols

What is an AR pistol legally?
An AR pistol is an AR-15-pattern firearm configured as a pistol — it has no stock (a pistol brace is used instead), a barrel under 16 inches, and is classified as a handgun under federal law. This classification is significant: AR pistols can be transported and stored differently than rifles in some states, and the short barrel is legal without NFA registration as a short-barrel rifle (SBR). An AR pistol becomes an SBR — requiring NFA registration — if a traditional rifle stock is attached.

What is the difference between an AR pistol and an SBR?
Both have short barrels, but an SBR has a traditional rifle stock while an AR pistol uses a pistol brace (or no brace). An SBR requires ATF Form 4 registration and approval (now free since the January 2026 stamp fee elimination, but still requires the approval wait time). An AR pistol with a brace requires no NFA paperwork. With the $200 fee gone, many buyers now choose to register their AR pistol as an SBR to use a traditional stock legally.

What caliber is best for an AR pistol?
.300 Blackout is purpose-built for short AR barrels — it achieves full powder burn in 9 inches and produces practical defensive performance where 5.56 loses significant velocity in short barrels. 5.56 NATO is still effective from 10.5-inch AR pistol barrels but loses more velocity than .300 BLK. 9mm AR pistols (CMMG Banshee, Sig MPX) eliminate the rifle caliber entirely for close-range use with lower recoil and noise.

Are AR pistols good for home defense?
Yes — a quality AR pistol in .300 Blackout or 5.56 is highly effective for home defense. The short barrel makes it more maneuverable in hallways and rooms than a full-length rifle. A suppressed .300 Blackout AR pistol is one of the most capable and hearing-safe home defense options available, particularly after the NFA fee elimination made suppressor ownership more accessible.

See Also: AR-15 Rifles • Short-Barrel Rifles • .300 Blackout Ammo • Suppressors • ATF eForms