The CMMG Resolute MK4 6mm ARC upper receiver assembly delivers 6mm ARC chambering in a 16.1″ barrel configuration, designed for AR-15 platform lowers.
- Caliber: 6mm ARC
- Type: Complete Upper Receiver Assembly
- Compatible Lower: AR-15 / MULTI
- Barrel Length: 16.1″
- Material: 4140 Chrome Moly Steel Barrel, 7075-T6 Aluminum Receiver
- Finish: Black Salt Bath Nitride Barrel, Type III Hardcoat Anodized Receiver
- Includes: Upper receiver assembly with barrel and handguard (verify complete contents with manufacturer)
- Installation: Fits standard AR-15 lower receivers, requires compatible BCG and charging handle
