CMMG Upper Group Resolute for MK4 .22LR 17" Black

The CMMG Upper Group Resolute for MK4 .22LR 17" Black is purpose-built for shooters seeking an economical, low-recoil training solution without sacrificing reliability or modularity. Whether you're a law enforcement trainer running qualification drills, a military small-arms instructor cutting ammunition costs, or a civilian marksman honing fundamentals, this .22 LR upper transforms any standard AR15 lower into a dedicated rimfire platform. The Resolute platform excels in environments where high-volume repetition is essential—from firearms safety courses to transition-drill practice—because it delivers consistent 22 LR ballistics with the ergonomic familiarity of the AR15 platform.

Built by CMMG Inc., a manufacturer with deep roots in AR platform engineering, this upper assembly features a 17-inch barrel optimized for .22 LR velocity and accuracy at typical indoor and outdoor ranges. The Resolute design houses all critical components—barrel, bolt carrier group, and charging handle—in a single removable upper that mates seamlessly with standard AR15 lowers, eliminating the need for caliber-specific lower receivers. The black hard-coat anodize finish resists corrosion and wear during extended training cycles, while the modular architecture allows rapid caliber swaps by simply removing the takedown pins. CMMG's engineering ensures that .22 conversion magazines feed reliably, a critical factor for training consistency and shooter confidence.

Law enforcement academies, military basic marksmanship instructors, and competitive shooters benefit most from this upper's cost-per-round efficiency and zero-recoil ergonomics, which isolate trigger control and sight picture fundamentals. The 4.73-pound weight and compact 31.5-inch overall length make it ideal for confined training spaces or vehicle-mounted platforms. Installation requires no permanent modifications—simply attach to any AR15 lower with standard takedown pins and load CMMG .22 conversion magazines. Compatibility is universal across standard AR15 lowers, including fixed and adjustable stock configurations, making this a versatile addition to existing AR platform arsenals.