Overview Reviews Product Description Includes: Upper Receiver 300 BO BARREL 10.5″ XTS Charging Handle XTS Forward Assist XTS Ejection Port Cover 9″ M-LOK RAIL Black Gas Block Gas Tube Bird Cage Muzzle Brake Product Videos Custom Field Product Reviews Write a Review Write a Review × MCS AR-15 10.5" 300 BO UPPER - BLUE Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *