Proof Research PR15 128688 18" 6mm ARC Stainless Steel AR Barrel

This PROOF Research PR15 steel AR-15 barrel is an 18-inch stainless steel barrel chambered in 6mm ARC, designed for AR-15-pattern rifles. It uses PROOF's PR15 contour and 1:7.5 twist rate to stabilize a wide range of 6mm bullets, and is machined from stainless steel for durability and corrosion resistance. The barrel features a threaded muzzle with a 5/8x24 pattern and a 0.750-inch gas journal, and it is configured with a rifle +1 length gas system tailored to the 6mm ARC cartridge.\n\n- 18-inch stainless 6mm ARC PR15 AR-15 barrel\n- 1:7.5 twist rifling and .750 gas journal\n- Rifle +1 gas system and 5/8x24 threaded muzzle\n\nDesigned by PROOF Research for the AR-15 platform, this PR15 steel barrel gives builders a dedicated 6mm ARC option with proven gas system geometry. It is well suited for precision-focused setups where stainless construction and threaded muzzle compatibility are desired.