BC-15 .300 Blackout Right Side Charging Upper 10.5" Parkerized Heavy Barrel 1: 8 Twist Pistol Length Gas System 9.5" MLOK - $179 This BCA AR-15 complete 300 Blackout pistol length upper has a 10.5" heavy barrel with a parkerized finish, and features a 1: 8 twist rate, with a pistol length gas