CMMG Resolute Mk4 6.5 Grendel 16.1" Rifle - Armor Black

The CMMG Resolute Mk4 6.5 Grendel 16.1" rifle is purpose-built for shooters who need medium to long-range ballistic performance without hauling a full-size platform. The 6.5 Grendel cartridge was designed from the ground up for the AR-platform, and this Resolute variant leverages that heritage with a compact 16.1" barrel that still delivers flat-shooting accuracy downrange. At 6.4 lbs, it's nimble enough for hunting or field work where weight matters, yet the 6.5 Grendel's heavier bullet selection gives you the punch that pistol-caliber carbines simply can't match.

This rifle comes dressed with CMMG's ZEROED suite of components—from the ambi charging handle and drop-in trigger to the muzzle brake and safety selector—so you get a cohesive, reliable platform out of the box. The EML15 M-LOK handguard strips away unnecessary weight while keeping attachment points where you need them: 3, 6, 9, and 12 o'clock for mounting optics, lights, or supports. A direct-impingement operating system keeps things simple and proven, while the billet upper and forged lower receivers ensure durability through hard use.

The Resolute's Cerakote armor black finish resists the elements, and the 6-position RipStock lets you dial in length-of-pull for your shooting style. Whether you're building a long-range hunter, a precision field rifle, or a versatile carbine that fills the gap between pistol and full rifle, the Resolute Mk4 in 6.5 Grendel delivers ballistic capability in a package that doesn't feel oversized.

Key Features

• 6.5 Grendel cartridge optimized for medium to long-range performance in an AR-platform rifle
• 16.1" 416 stainless steel barrel with 1:8 twist and CMMG ZEROED muzzle brake
• Lightweight at 6.4 lbs—compact carbine without sacrificing reach or power
• CMMG ZEROED ambi charging handle, drop-in trigger, and safety selector for smooth operation
• EML15 M-LOK handguard with attachment points at 3, 6, 9, and 12 o'clock
• Direct-impingement system with non-adjustable 0.750" gas block for reliability
• Billet 6061-T6 aluminum upper and forged 7075-T6 aluminum lower receivers
• RipStock with 6-position receiver extension and ambi sling plate for customizable fit
• Cerakote armor black finish for corrosion resistance

Specifications

Frequently Asked Questions

What's the advantage of 6.5 Grendel for a carbine?

The 6.5 Grendel was purpose-designed for AR-platform rifles and delivers superior ballistic performance compared to 5.56 NATO or 7.62x39 out of a 16.1" barrel. You get flatter trajectory and better energy retention at distance without the bulk or recoil of larger calibers—ideal for hunting, precision shooting, and field applications where medium to long-range capability matters.

Is the RipStock adjustable?

Yes. The CMMG RipStock features 6-position adjustment on the receiver extension, allowing you to customize length-of-pull to your shooting preference or gear configuration.

What does the rifle come with?

The Resolute Mk4 ships with a 10-round CMMG magazine and the complete CMMG ZEROED component suite, including the ambi charging handle, drop-in trigger, muzzle brake, safety selector, and trigger guard. It is ready to run out of the box.

Can I attach a suppressor or other muzzle devices to this rifle?

The barrel features a 5/8 x 24 muzzle thread, which is standard for many aftermarket suppressors and muzzle devices. The rifle comes with a CMMG ZEROED muzzle brake; you can replace it with a suppressor or other threaded accessory as needed.