CMMG Dissent MK4 .300 AAC Blackout 6.50in Upper

The CMMG DISSENT MK4 upper is a compact AR-platform upper group chambered in .300 AAC Blackout with a 6.50-inch barrel. It employs CMMG's patent-pending Compact Action and radial delayed blowback system with a fixed ejector, housing the action and recoil assembly within the upper receiver to reduce bulk. The forward non-reciprocating left-side charging handle permits quick bolt operation while maintaining support-hand position. This upper ships with a zeroed linear compensator, a 4.60" M-LOK handguard, and a 1913 Picatinny end plate for AR-platform integration.

Key Specifications

• The model is CMMG Dissent MK4 Upper.
• The caliber is .300 AAC Blackout.
• The barrel measures 6.50 inches.
• The barrel finish is Black.
• The handguard is a 4.60" M-LOK with an Armor Black finish.
• The rate of twist is 1:10.
• The operating system uses radial delayed blowback with a fixed ejector.
• The charging handle is a left-side, non-reciprocating design.
• Includes a zeroed linear compensator and a 1913 Picatinny end plate.
• Designed to fit AR-platform lowers for compact builds.

Compact and feature-rich, this upper provides a practical solution for short-barrel AR-platform projects where overall length and modular mounting options matter. Its combination of CMMG's Compact Action, left-side charging, and M-LOK handguard supports streamlined accessory integration and functional handling in confined environments.