CMMG Dissent MK4 5.7x28mm 6.50″ Upper, Left-Side Charging

Key Specifications

• The caliber is 5.7 x 28 mm.
• The barrel length is 6.50″.
• The handguard is a 4.60″ M-LOK design.
• The finish is Armor Black.
• The charging handle is left-side, non-reciprocating.
• The action employs Radial Delayed Blowback with a fixed ejector.
• Includes a zeroed linear compensator as specified in the product name.
• Features a 1913 Picatinny rail end plate for use in place of a lower receiver buffer tube.
• The twist rate is 1:9.

The CMMG DISSENT MK4 upper group is a compact AR-platform assembly that integrates CMMG’s patent-pending Compact Action to house the action and recoil components within the upper receiver, reducing overall bulk. It uses Radial Delayed Blowback technology with a fixed ejector and a forward non-reciprocating left-side charging handle for practical bolt operation. The package includes a 4.60″ M-LOK handguard, a zeroed linear compensator, and a 1913 Picatinny rail end plate for mounting options on AR-style builds.

Designed for shooters seeking a compact, straightforward upper for AR-platform projects, the DISSENT MK4 balances short overall length with a user-friendly charging solution and modular handguard compatibility, making it well suited for compact defensive or range-focused configurations.