CMMG RESOLUTE MK57 | 5.7×28 | 16.1in Armor

The CMMG RESOLUTE MK57 is a carbine-length rifle chambered in 5.7x28mm that emphasizes lightweight handling and low felt recoil. The Mk57 platform is built to accept FN Five-seveN style magazines while retaining AR-style features such as last-round bolt hold open. The RESOLUTE series pairs a 16.1-inch barrel and the CMMG ZEROED suite of parts to offer an ergonomic, accessory-ready carbine. A reliable red-dot optic such as the Vortex SPARC AR is a practical, sub-$1000 choice that complements the RESOLUTE’s handling and close-to-mid-range performance.

Product Specifications

• The UPC is 810144728278.
• The platform is Mk57.
• The caliber is 5.7x28mm.
• The operating system is Radial Delayed Blowback.
• The barrel length is 16.1 inches.
• The barrel twist is 1:9.
• The barrel contour is MT.
• The barrel material is 4140CM SBN.
• The muzzle device is a CMMG ZEROED Muzzle Brake.
• The muzzle thread is 1/2 x 28.
• The upper receiver is Billet 6061 T6 Aluminum.
• The lower receiver is Mk57 Forged 7075 T6 Aluminum.
• The hand guard is CMMG EML15 M-LOK.
• The finish is Cerakote.
• The magazine included is a 20rd Promag.
• The weight is 6.2 lbs.
• The overall length is 32.5 inches.

The RESOLUTE MK57 combines CMMG’s ZEROED component set with the Mk57 platform to create a carbine that is lightweight, modular, and straightforward to accessorize. The EML15 M-LOK handguard reduces weight while providing mounting points where they matter, and the RipStock paired with the 6-position receiver extension allows fast, repeatable shoulder indexing. The platform’s compatibility with FN Five-seveN style magazines simplifies logistics for users who run both pistols and carbines in 5.7x28mm.

Owners often praise the platform for its light recoil and the convenience of FN Five-seveN magazine compatibility.