BC-15 .300 Blackout Right Side Charging Upper 8.5" Parkerized Heavy Barrel 1: 8 Twist Pistol Length Gas System 6.5" MLOK - $189.99 This BCA AR-15 complete 300 Blackout pistol length upper has a 8.5" heavy contour barrel with a parkerized finish, and features a 1: 8 twist rate, with a pistol length