CMMG Resolute Upper | 5.7x28mm | 16.1 in | 57B40E4AB

The CMMG Resolute Upper Group is a factory-complete AR-platform upper built around the 5.7x28mm chambering and a 16.1 inch barrel. It pairs a billet 6061 T6 aluminum upper with a free-float EML15 M-LOK handguard finished in Armor Black Cerakote. The assembly includes CMMG ZEROED accessories and is intended for range use and PDW-style carbine applications.

Product Specifications

• The UPC is 810097504318.
• The manufacturer is CMMG.
• The model is Resolute Upper Group.
• The manufacturer’s part number is 57B40E4AB.
• The caliber is 5.7x28mm.
• The platform is Mk4 Mk57 (AR-platform).
• The operating system is Radial Delayed Blowback.
• The barrel measures 16.1 inches for balanced handling.
• The barrel twist is 1:9.
• 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 handguard is a CMMG EML15 M-LOK free-float design.
• The finish is Cerakote Armor Black.

This Resolute Upper Group provides a ready-to-run AR-platform upper when paired with a compatible lower and the correct magazines. The combination of a 16.1-inch 4140CM SBN barrel, M-LOK free-float handguard, and factory ZEROED accessories makes it well suited for precision-oriented range sessions and PDW-style carbine configurations where a compact, fast-handling upper is desired.