Bushmaster 91823 Patrolmans Carbine (M4 A3) Complete Upper 223 Remington/5.56 NATO 16 in FH 4150 Chrome Moly Vanadium Steel Chrome-Lined Black Brl Finish

Built on the versatile Bushmaster modular MSR upper platform, this Patrolman's Carbine (M4 A3) upper receiver assembly has a 16" M4-profile barrel made of 4150 chrome-moly-vanadium steel with hard chrome-lining in both bore and chamber for extended barrel life. It has an A2 birdcage-type flash hider, and front sight post with bayonet lug. The flattop receiver features integral brass deflectors and a black hard anodized finish. Each bolt carrier assembly is factory headspaced, proofed, test fired, and ready to use on your on existing MSR-type lower receiver.