CMMG Dissent MK4 5.7x28mm 6.50″ Upper

The CMMG DISSENT MK4 upper is a compact AR-platform upper group built around CMMG's Compact Action and Radial Delayed Blowback system. It houses the action and recoil assembly in the upper receiver to reduce overall length and bulk compared with traditional AR pistol configurations. The forward non-reciprocating left-side charging handle enables bolt manipulation without taking the rifle off target, and the upper includes a 1913 Picatinny rail end plate for use in place of a lower buffer tube.

Key Specifications

• The caliber is 5.7 x 28 mm.
• The barrel measures 6.50".
• The barrel finish is Black.
• The overall finish type is Armor Black.
• The handguard is a 4.60" M-LOK configuration.
• The handguard finish is Armor Black.
• The assembly includes a Zeroed Linear Comp.
• The upper features a left-side non-reciprocating charging handle.
• The end plate provides a 1913 Picatinny rail interface to use in place of a lower receiver buffer tube.
• The rifling twist rate is 1:9".

The DISSENT MK4 upper is designed for builders and users seeking a compact, purpose-built AR upper for platforms chambered in 5.7x28mm. Its compact action, left-side charging ergonomics, and modular M-LOK handguard make it suitable for compact builds where length and controllability are priorities.