• CMMG AR 300 Blackout 12.5" MR 4140CM SBN Barrel


    There is only 1 item left in stock.

    Perfect for building your custom AR15 upper group. Comes with properly installed M4 barrel extension. All barrel sub-assemblies are properly headspaced.


    Multi Role Profile
    4140 Chrome Moly
    Salt Bath Nitride Finish inside and out
    1:7 Twist
    300 AAC Blackout Chamber
    Threaded 5/8-24
    Pistol length gas port
    .750″ Gas Journal