CMMG Resolute MK4 Complete Upper Group – 6.5 Grendel 16.1″ Barrel

Upgrade your AR-platform rifle with the CMMG Resolute MK4 Complete Upper Group chambered in 6.5 Grendel with a 16.1″ barrel. Engineered by CMMG — one of America’s most trusted AR manufacturers — this complete upper group delivers the precision, reliability, and long-range capability that hunters, competitive shooters, and serious enthusiasts demand.

The 6.5 Grendel chambering offers a significant ballistic advantage over standard 5.56 NATO, providing flatter trajectories, superior energy retention at distance, and excellent terminal performance on medium to large game. Whether you’re reaching out across open fields in Florida or competing on the range, this upper delivers consistent, accurate performance.

Built on CMMG’s proven MK4 platform, this complete upper group is designed for straightforward installation onto any mil-spec AR-15 lower receiver, making it an ideal upgrade or build component. CMMG’s reputation for tight tolerances, quality materials, and rigorous quality control ensures you’re getting a product built to last.

**Key Features:**
– Chambered in 6.5 Grendel for superior long-range ballistic performance
– 16.1″ barrel configuration — legal for standard rifle builds without NFA considerations
– CMMG MK4 platform — compatible with mil-spec AR-15 lower receivers
– Complete upper group ready for installation
– Built by CMMG, a trusted American AR manufacturer

Available online with fast shipping nationwide or pick it up in person at Deep Roots Rifle Co in Eustis, Florida. Our knowledgeable staff is ready to help you find the right components to complete your build. Order today and take your AR platform to the next level.