Faxon Duty Series 16" Big Gunner 8.6 Blackout 4150 Nitride Carbine-Length Barrel

Faxon Duty Series 16″ Big Gunner 8.6 Blackout 4150 Nitride Carbine-Length Barrel

The Faxon Firearms 16″ Big Gunner 8.6 Blackout Carbine-Length Barrel is a purpose-driven solution for AR-10 builders who want to unlock the full potential of the 8.6 Blackout cartridge. Designed around a hybrid contour and fast twist rate, this barrel maximizes energy on target while maintaining an efficient balance of weight, accuracy, and handling. Whether you’re setting up for suppressed hunting, short-range knockdown power, or a unique range build, this 8.6 BLK barrel is ready for the job.

Crafted from 4150 CMV steel and finished with a full QPQ salt bath nitride treatment inside and out, the barrel is built to endure thousands of rounds in tough conditions. The 1:3 twist rate is one of the defining features of this barrel—it’s specifically optimized to stabilize heavy subsonic projectiles that are commonly used in 8.6 Blackout applications. The result is excellent terminal performance at close-to-mid range, particularly when paired with a suppressor and expanding bullets.

The Big Gunner profile is thicker near the chamber and gas block to retain accuracy under heat, then tapered forward to reduce weight at the muzzle. A carbine-length gas system supports smooth cycling and enhanced reliability, even with subsonic ammunition. The gas block journal diameter is .875″, and the barrel is threaded with M18x1.5 pitch, ready for direct suppressor mounting or adapter use. Additionally, the DPMS Gen 1 .308 barrel extension ensures proper compatibility with standard AR-10 upper receivers.

Each barrel is magnetic particle inspected for integrity and includes an 11-degree target crown to maintain consistent bullet release. The 16″ length gives you solid velocity while remaining compact enough for maneuverability in the field.