CMMG Resolute MK4 Upper 6mm ARC 16.1″ Black

The CMMG Resolute MK4 complete upper group is chambered in 6mm ARC and built for use with standard AR-15 pattern lower receivers. It pairs a 16.1" 416SS SBN barrel and CMMG ZEROED accessories to provide a complete, drop-in upper option for precision-oriented builds. The upper features a billet 6061 T6 aluminum receiver and a CMMG EML15 M-LOK handguard.

Key Specifications

• Chambering: 6mm ARC designed for use with AR-15 pattern lowers.
• Barrel length: 16.1 inches for extended-range performance while remaining AR-15 compatible.
• Barrel material and finish: 416SS SBN construction with Cerakote standard finish.
• Barrel twist: 1:7.5 twist rate as specified by the manufacturer.
• Muzzle device: CMMG ZEROED Muzzle Brake supplied with the upper.
• Muzzle thread: 5/8 x 24 thread pattern for compatible muzzle devices.
• Gas system: Rifle gas port location with a 0.750 non-adjustable gas block.
• Handguard: CMMG EML15 M-LOK for accessory attachment and modularity.
• Upper receiver: Billet 6061 T6 Aluminum construction.
• Included accessories: ZEROED bolt carrier group, ZEROED ambidextrous charging handle, and the ZEROED polymer dust cover.

This Resolute MK4 upper delivers a ready-to-install platform for shooters seeking the ballistics of 6mm ARC in an AR-15 format. With a durable 416SS barrel, a billet aluminum receiver, and CMMG ZEROED components included, it provides a balanced combination of build quality and out-of-the-box completeness for precision-capable configurations.