CMMG Resolute Mk4 5.7x28mm Rifle, 16.1" Barrel, Coyote Tan Finish

The CMMG Resolute Mk4 5.7x28mm rifle bridges a practical gap: it delivers rifle-length ballistics and accuracy in a compact, handy package that won't feel oversized for vehicle or home defense. Built on CMMG's proven Mk4 AR platform with radial delayed blowback operation, this 16.1\" barrel rifle in 5.7x28mm gives you serious velocity and energy downrange without the footprint or recoil of larger rifle calibers. The coyote tan cerakote finish blends durability with a purposeful look.

What sets the Resolute apart is thoughtful engineering: CMMG's proprietary magazines fit standard AR15 magwells, meaning you can leverage existing ammunition and accessories without learning an entirely new system. The EML15 M-LOK handguard strips unnecessary rail real estate to save weight while keeping attachment points where they matter—12, 3, 6, and 9 o'clock—so you can mount your optics, lights, or grips exactly how you need them. The rifle comes dressed with CMMG's full ZEROED suite: ambi charging handle, drop-in trigger, 60/90-degree safety, and matching trigger guard and grip. All that runs together on a 6-position fastback receiver extension with ambidextrous sling plate and the legendary RIPSTOCK for shooter control.

At 6.4 lbs and 32.5\" overall length, the Resolute Mk4 handles fast in tight spaces yet maintains the sight radius and energy of a proper carbine. The 1:9 barrel twist stabilizes the caliber, and the 1/2 x 28 muzzle threads accept a ZEROED muzzle brake for recoil management. A 32-round magazine ships with the rifle, giving you serious capacity without the bulk. This is a working rifle for shooters who want modular 5.7x28mm performance without compromise.

Key Features

• Radial delayed blowback operation designed specifically for 5.7x28mm ballistics
• 16.1\" barrel (1:9 twist) balances velocity with handling in compact form
• Proprietary magazines use standard AR15 magwells for maximum compatibility and modularity
• CMMG EML15 M-LOK handguard with 4-point mounting slots and minimal weight
• Complete CMMG ZEROED parts package: ambi charging handle, drop-in trigger, ambi safety, matched grip and guard
• RIPSTOCK receiver extension with ambidextrous sling plate for control and support
• Coyote tan cerakote finish for durability and a professional appearance
• 1/2 x 28 muzzle threads with CMMG ZEROED muzzle brake
• Lightweight at 6.4 lbs, compact at 32.5\" overall length
• Ships with 32-round magazine

Specifications

Frequently Asked Questions

Is this rifle compatible with standard AR-15 magazines?

No. The CMMG Resolute Mk4 5.7x28mm uses CMMG's proprietary 5.7x28mm magazines that fit standard AR15 magwells. This design maximizes modularity while being optimized for the 5.7x28mm cartridge. The rifle ships with a 32-round magazine.

What kind of ballistic performance does a 16.1\" 5.7x28mm barrel deliver compared to pistol calibers?

The 16.1\" barrel length in a rifle platform delivers significantly more velocity, energy, and sight radius than a pistol-caliber firearm, giving you rifle-like ballistic performance in a compact, handy package. The 1:9 barrel twist is optimized for the 5.7x28mm cartridge.

What comes included with the rifle?

The rifle ships with a 32-round CMMG proprietary magazine and is equipped with CMMG's complete ZEROED accessory suite, including ambi charging handle, drop-in trigger, ambi safety, pistol grip, trigger guard, muzzle brake, and RIPSTOCK receiver extension with ambidextrous sling plate.

Is the handguard set up for mounting accessories?

Yes. The CMMG EML15 M-LOK handguard features M-LOK attachment slots at the 12, 3, 6, and 9 o'clock positions, giving you plenty of real estate to mount lights, laser devices, and other accessories. The design minimizes unnecessary rail while keeping mounting points where shooters need them.