Shop › CMMG UPPR RSLT MK4 6MM ARC 16.1" BLK CMMG UPPR RSLT MK4 6MM ARC 16.1" BLK $899.95 sold out CMMG Resolute MK4, Upper Receiver, 6MM ARC, 16.1" Barrel, Cerakote Finish, Armor Black 60B1091-AB Sold Out Added! CMMG Resolute MK4, Upper Receiver, 6MM ARC, 16.1" Barrel, Cerakote Finish, Armor Black 60B1091-AB