Here are the final pieces you’ll need to complete that Retro AR you’ve been working on. We’ve made it easy with our complete M4A2 upper assembly, which includes all the authentic pieces you’ll need to finish that retro “Heat”-styled rifle.  Featuring an A2 Carry Handle, 16″ Chrome Lined Barrel, Chrome Lined Bolt Carrier Group, and that authentic A2 front sight base, you’re two pins away from finishing that retro rifle you’ve been dreaming about. Best of all, you’ll have the Bushmaster® quality built in. Features & SpecificationsCaliber: 5.56 NATO / .223 REMBarrel Length: 16″Barrel Material: 4150 CMVBarrel Finish: Phosphate Chrome LinedBarrel Thread Pitch: 1/2 x 28Twist Rate: 1:7Weight: 4.3 lbOverall Length: 24.5 inGas System: Carbine LengthLower Receiver Material: 7075 Aluminum AlloyUpper Receiver Material: 7075 Aluminum AlloyUpper Receiver: A2Bolt Carrier Group Finish: Chrome Lined PhosphateBolt: MPI & HPT TestedHandguard: M4 Heat ShieldsMuzzle Device: A2 Flash HiderFront Sight: NON F-Marked A2 FSBRear Sight: 8/3 Fixed Carry HandleProudly Made In: U.S.A.