BSF Barrels AR Carbon Fiber Barrel AR-15 .300 AAC Blackout 16 in Pistol Length 1-7 Twist 5/8x24 Thread .875 OD Gray FP1516B0087. 300 AAC Blackout Carbon Fiber Barrel. These Rifle Barrels by BSF Barrels are constructed from .300 AAC Blackout chamberings...