CMMG Upper Mk4 T 300 Blackout


  • The Mk4 T Upper Group introduces CMMG’s RKM series of KeyMod free float hand guards with this 300 AAC Blackout completed upper receiver build.
  • Caliber: 300 Blackout
    Barrel: 16.1″, 1:7 twist, medium taper, 4140CM, SBN
    Muzzle: A2 comp., threaded 5/8-24
    Hand Guard: CMMG RKM11 KeyMod hand guard
    Receiver: Forged 7075-T6 AL M4 type upper
    Gas Port Location: Carbine


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