The CMMG Resolute MK4 (CMMG part no. 55A9D0BAB) is a 5.56 NATO AR-15 built on CMMG’s Mk4 platform, finished in Armor Black and fitted with the company’s full ZEROED parts package. CMMG pairs a 16.1-inch medium-taper barrel in 4140 chrome moly steel with a salt-bath nitride coating, run on a direct impingement gas system with a mid-length port and a non-adjustable .750 gas block. A billet 6061-T6 aluminum upper meets a forged 7075-T6 lower, and the CMMG EML15 M-Lok handguard keeps M-Lok slots at the expected 3, 6, 9, and 12 o’clock positions while trimming weight from the previous full-length rail design. The legendary CMMG RipStock and a full ZEROED trigger, grip, and ambidextrous safety selector round out a carbine built for any AR-15 accessory in the aftermarket.

Key Specifications

• Chambered in 5.56 NATO/.223 Remington.
• Barrel length is 16.1 inches, medium-taper contour, in 4140 chrome moly steel.
• The barrel wears a salt-bath nitride coating.
• Rate of twist is 1:7 inches.
• The gas system is direct impingement, mid-length, with a non-adjustable .750 gas block.
• The muzzle wears a CMMG Zeroed muzzle brake, threaded 1/2×28.
• The upper receiver is billet 6061-T6 aluminum; the lower is forged 7075-T6 aluminum.
• The handguard is the CMMG EML15 M-Lok design.
• The stock is the CMMG RipStock.
• The safety selector is a CMMG Zeroed 60/90-degree ambidextrous design.

Frequently Asked Questions

What is the CMMG RipStock? CMMG’s proprietary buttstock fitted standard on the Resolute line.

Is the safety selector ambidextrous? Yes, a CMMG Zeroed 60/90-degree design.

What magazine does this rifle use? A Magpul 30-round PMAG.

Buy the CMMG Resolute MK4 5.56 NATO Rifle, 16.1-inch, Armor Black

This Resolute MK4 is a feature-packed pick from our AR rifles lineup. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.