CMMG Resolute MK4 Complete Upper Group .22 LR 16.1" Black – 22B820FAB

The CMMG Resolute MK4 Complete Upper .22 LR 16.1" Black (Part Number 22B820FAB, UPC 840442502676) is a premium, factory-assembled complete upper receiver designed to convert your standard AR-15 lower receiver into a reliable and accurate .22 LR rifle. Built on CMMG’s proven Resolute MK4 platform, this complete upper features a 16.1-inch barrel, a durable black finish, and high-quality components that deliver smooth cycling and excellent accuracy with inexpensive .22 LR ammunition. Whether you’re looking for an affordable training platform, a fun plinker, or a dedicated rimfire rifle, the CMMG Resolute MK4 .22 LR upper offers outstanding performance and value.

Key Features of the CMMG Resolute MK4 .22 LR Complete Upper

Why Choose the CMMG Resolute MK4 .22 LR Complete Upper?

The CMMG Resolute MK4 .22 LR Complete Upper stands out as one of the most reliable and well-built .22 LR conversion uppers available for the AR-15 platform. Unlike many budget .22 LR uppers that suffer from feeding and extraction issues, CMMG engineered this upper with a robust blowback operating system and quality components that deliver consistent performance. The 16.1-inch barrel provides an excellent balance of velocity, accuracy, and maneuverability, making it ideal for both range training and small game hunting.

This complete upper comes fully assembled with a bolt carrier group, charging handle, and handguard, allowing for quick and easy installation onto any standard AR-15 lower receiver. The black finish provides a professional appearance while offering good corrosion resistance. CMMG’s reputation for quality manufacturing ensures that this upper will provide years of reliable service with minimal maintenance.

Best Uses for the CMMG Resolute MK4 .22 LR Upper

• AR-15 .22 LR Conversion: Turns any AR-15 lower into an affordable rimfire rifle
• Training & Practice: Low-cost alternative for high-volume training and marksmanship practice
• Plinking & Recreational Shooting: Fun and economical for casual range days
• Small Game Hunting: Effective for squirrels, rabbits, and other small game
• Competitive Shooting: Suitable for rimfire competitions and steel challenge events
• Suppressor Host: Excellent platform for .22 LR suppressors
• Youth & New Shooter Training: Low recoil makes it ideal for teaching new shooters

Performance and Design Advantages

The CMMG Resolute MK4 .22 LR Complete Upper offers several key performance advantages. The 16.1-inch barrel provides good muzzle velocity for .22 LR ammunition while keeping the overall length manageable. The blowback operating system is simple and reliable, with fewer parts to maintain compared to gas-operated systems. The M-LOK compatible handguard allows for easy attachment of lights, grips, and other accessories. CMMG’s attention to detail in the bolt carrier group and extractor design results in excellent feeding and extraction reliability, even with a wide variety of .22 LR ammunition. The complete upper design means users can quickly swap between their standard 5.56 upper and this .22 LR upper without any permanent modifications to their lower receiver.

Who Should Buy the CMMG Resolute MK4 .22 LR Complete Upper?

The CMMG Resolute MK4 Complete Upper .22 LR 16.1" Black (22B820FAB) is an excellent choice for AR-15 owners who want an affordable and reliable way to shoot .22 LR ammunition in their existing platform. It is particularly well-suited for competitive shooters looking for a dedicated rimfire upper, instructors who train new shooters, hunters who want a quiet small game rifle, and anyone who wants to enjoy high-volume shooting without the high cost of centerfire ammunition. If you’re looking for a quality .22 LR upper that offers better reliability and build quality than most conversion kits, the CMMG Resolute MK4 is a top-tier option that delivers professional performance at a reasonable price.

Transform your AR-15 into a versatile .22 LR rifle with the CMMG Resolute MK4 Complete Upper. The 22B820FAB delivers reliable performance, excellent accuracy, and easy installation for training, plinking, and more.The End ```