The Radical Firearms RF-15 10.5 AR pistol (brand part no. FP10.5-5.56M4-10RPR) from Radical Firearms is a compact 5.56 NATO pistol built on forged 7075-T6 MIL-STD receivers. A 10.5-inch M4-profile 4140 chrome moly vanadium barrel with a Melonite finish and 1:7 twist sits under a 10-inch RPR free-float M-LOK rail. The carbine-length gas system keeps recoil balanced, and the pistol buffer tube keeps the setup compact. Radical lists range training, compact defensive setups and vehicle builds as its intended uses. It is a straightforward, accessory-friendly AR pistol for shooters who want a longer rail than the 7.5-inch version.

Key Specifications

• The chambering is 5.56 NATO, a widely available cartridge with deep support in the AR-15 platform.
• The barrel measures 10.5 inches, an M4-profile length that balances handling and velocity.
• The barrel is 4140 chrome moly vanadium steel with a Melonite finish, a combination chosen for corrosion resistance and long barrel life.
• The twist rate is 1:7, which stabilizes a wide range of modern bullet weights.
• The gas system is carbine length with a low-profile .750 gas block, which supports reliable cycling and balanced recoil.
• The handguard is a 10-inch RPR free-float M-LOK thin rail, giving extended mounting space for optics, lights and grips.
• The muzzle device is an A2 flash hider on 1/2×28 threads, so other muzzle devices can be swapped in.
• The receivers are forged 7075-T6 aluminum with a Type III anodized finish, built to MIL-STD dimensions.
• The barrel extension has M4 feed ramps, which helps with feeding reliability.
• Magazine capacity is 30 rounds, the standard AR-15 magazine size.

Frequently Asked Questions

How long is the rail on this Radical pistol? It uses a 10-inch RPR free-float M-LOK thin rail, which frees the barrel from handguard pressure and provides extra space for accessories.

Does this pistol use a carbine or pistol length gas system? This 10.5-inch version uses a carbine-length gas system with a low-profile .750 gas block, which the maker says supports reliable cycling and a balanced recoil impulse.

What muzzle device and thread does it have? It carries an A2 flash hider on a 1/2×28 threaded barrel, the common AR-15 pattern for muzzle devices.

Buy the Radical Firearms RF-15 RPR AR Pistol, 5.56 NATO, 10.5-Inch, 30-Round

Radical Firearms builds this pistol in Texas on forged MIL-STD receivers, and it arrives ready for a red dot, light and grip. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL, and check out more AR pistols while you are here.