CMMG 28B260CMB Resolute | .22 ARC | 16.10″ Barrel

Built to adapt the .22 ARC cartridge to the AR-15 Mk4 platform, the CMMG Resolute 28B260CMB provides increased ballistic performance while maintaining AR-15 compatibility. The upper features a 16.10″ barrel produced from 4140 steel and pairs with a 15″ M-LOK handguard constructed from 7075-T6 aluminum. It is intended for shooters seeking a compact, rifle-length barrel package that offers flat trajectories and efficient cartridge performance. Typical applications include precision target work and varmint hunting.

Product Specifications

• Manufacturer: CMMG.
• Manufacturer part number: 28B260CMB.
• Caliber/Gauge: .22 ARC.
• The barrel measures 16.10 inches for a balance of velocity and handling.
• The barrel material is 4140 steel.
• The handguard style is a 15″ M-LOK configuration.
• The handguard is constructed from 7075-T6 aluminum.
• The rifling twist rate is 1:7.
• Platform compatibility: AR-15 (Mk4).
• Category: AR15 Uppers.
• UPC: 810148627355.

The Resolute 28B260CMB balances durable materials and AR-15 compatibility to deliver a reliable .22 ARC upper suited for precision shooting and field use. Its combination of a 16.10″ 4140 steel barrel, 1:7 twist rate, and a long 15″ M-LOK 7075-T6 handguard gives shooters a versatile platform for consistent groupings and efficient follow-up shots. Designed with practical use in mind, this upper integrates into Mk4 AR-15 builds where a .22 ARC solution is desired.