Proof Research AR-Style Barrel 6mm ARC 16" 1:7.5 Twist 416R Stainless Carbon Fiber Rifle Length - Threaded

The Proof Research AR-Style Barrel is a match-grade drop-in barrel designed for the AR-15 platform and chambered in 6mm ARC. The 16" barrel is built around a 416R stainless steel core wrapped in a carbon fiber sleeve - a Proof Research signature construction that dramatically reduces weight compared to a traditional steel contour while adding barrel rigidity and improving heat dissipation for cooler, longer-lasting performance across sustained strings of fire.

Chambered for the 6mm ARC cartridge, this barrel features a 1:7.5" twist rate optimized to stabilize modern high-BC projectiles. The barrel is configured for a rifle length gas system with a .750" gas journal diameter, and the muzzle is threaded and ready to accept your preferred muzzle brake, compensator, or suppressor mount.

No iron sights are installed, making this barrel an ideal foundation for a custom build paired with a free-float handguard and your choice of optic. Whether you are assembling a lightweight 6mm ARC hunting rifle, a precision DMR, or a suppressed tactical carbine, this Proof Research barrel delivers the accuracy, weight savings, and thermal performance that custom rifle builders demand.