CMMG DISSENT 5.7x28mm 6.5in Upper Receiver 1-9 Twist 1/2 X 28 TPI Armor Black. 7x28mm personal defense cartridge has found home with the purposefully designed 6.5 DISSENT upper group. This DISSENT upper group comes complete with BCG lower receiver 1913 picatinny rail end plate and the choice of seven Cerakote finishes to make it uniquely you. All you need is a Mk4/mil-spec AR15 lower receiver or CMMG Mk57 lower receiver. Its no secret that pistol stabilizing braces have been a target for scrutiny over the years and those that enjoy building their own AR pistols have wondered what will come out of all the uncertainty. DISSENT is our answer. Utilizing our patent pending Compact Action and Radial Delayed Blowback technology DISSENT upper groups house the entire action and recoil assembly in the upper receiver resulting in less bulk and length than traditional AR pistols. The forward non-reciprocating side charger allows for quick bolt operation without coming off target. DISSENT Upper groups include a 1913 Picatinny rail end plate to use in place of the lower receiver buffer tube. Specifications for CMMG DISSENT 5.7x28mm 6.5in Upper Receiver: Manufacturer: CMMG Caliber: 5.7x28mm Barrel Length: 6.5 in Barrel Twist Rate: 1-9 Threads per Inch: 1/2x28 Muzzle Device: Zeroed Linear Compensator Fabric/Material: Aluminum Gun Rail: M-LOK Gun Make: CMMG Condition: New Condition Quality: Excellent Condition Details: Other Magazine Included: No Package Contents: CMMG DISSENT 5.7x28mm 6.5in Upper Receiver CMMG 57BA8AE-AB: DISSENT 5.7x28mm 6.5in Upper Receiver 1-9 Twist 1/2 X 28 TPI Armor Black