AR-15 Pistols

Impact Guns has carried AR-15 pistols since they entered the mainstream market, and our staff has handled hundreds of configurations across every major platform. Whether you’re looking for a compact 5.56mm home defense build, a suppressor-ready 300 Blackout, or a pistol-caliber carbine in 9mm, we stock options at every price point with genuine in-house expertise to back them up.

Read our full AR-15 Pistol Buying Guide ↓

What Is an ARP Gun?

“ARP” is a widely used slang term for AR pistol — a short-barreled AR-15 platform firearm configured as a pistol rather than a rifle. ARP guns, ARP pistols, and AR pistols all refer to the same thing: an AR-15 lower receiver paired with a pistol upper (typically 7.5”–10.5” barrel), no stock, and a pistol brace or bare buffer tube. They’re compact, maneuverable, and available in multiple calibers. If you searched “ARP gun” or “ARP pistol,” you’re in the right place — every firearm in this category is an ARP.

What Makes an AR-15 a Pistol?

An AR-15 pistol is legally defined by its barrel length and the absence of a rifle stock. Barrels under 16 inches on an AR-platform with a pistol lower receiver classify the firearm as a pistol under federal law, not a short-barreled rifle (SBR). This distinction matters: AR pistols can be fitted with pistol braces, avoid NFA registration requirements, and are legal to purchase and own in most states without a tax stamp. If you’re coming from the rifle side of things, the key point is that the lower receiver’s original classification determines the legal category — always start with a pistol lower if you want a pistol.

Caliber Guide

5.56 NATO / .223 Remington — The standard AR caliber works well in pistol-length configurations down to about 7.5 inches. Expect more muzzle blast and fireball than a rifle-length barrel, but terminal performance at home defense ranges remains solid. Ammunition is widely available and affordable. Best for: general purpose, training, home defense.

300 Blackout — Purpose-built for short barrels. A 9-inch 300 BLK barrel loses almost no velocity compared to a 16-inch rifle, and it was specifically designed to suppress well. If you’re running or planning to run a suppressor, 300 BLK in subsonic is one of the best suppressed AR configurations available. Best for: suppressor use, home defense, hunting medium game.

9mm (Pistol Caliber) — Pistol-caliber AR pistols use Glock or Colt-pattern magazines and run on blowback operation. They’re softer shooting, quieter unsuppressed, and cheaper to feed than centerfire rifle calibers. Great for new shooters or anyone who wants a home defense option without the blast of a 5.56 pistol. Best for: beginner-friendly builds, suppressor hosts, range fun.

Barrel Length Guidance

Most AR pistols on the market run barrels between 7.5 and 10.5 inches. Here’s how to think about the tradeoffs:

7.5” — Maximum compactness, significant muzzle blast. Best indoors with a suppressor or for 300 BLK.
8.5” — A sweet spot for 300 BLK, near-optimal ballistics with a real reduction in overall length.
10.5” — The most popular pistol barrel length for 5.56. Good velocity, manageable blast, handy size. Our most-stocked configuration.