The CMMG Resolute 300 is a semi-automatic rifle chambered in 5.56 NATO / .223 Remington. It has a 16.1-inch barrel, holds 30 rounds, weighs approximately 6.7 lbs, and comes in a Black Cerakote finish. 
 

Key Specifications 

• Model: Resolute 300 
• Caliber: 5.56 NATO / .223 Remington 
• Barrel Length: 16.1 inches 
• Capacity: 30 rounds 
• Weight: Approximately 6.7 lbs 
• Finish: Black Cerakote 
   

Detailed Features 

The Resolute 300 has fully ambidextrous controls -- charging handle and safety selector -- so left-handed shooters can run it as naturally as right-handed ones. The Geissele SSA two-stage trigger has a smooth pull and quick reset, which translates to better shot-to-shot consistency. The CMMG RipStock is a six-position adjustable design that lets you dial in your length of pull. The CMMG SV muzzle brake manages recoil and muzzle rise during rapid fire.

Owners of the Resolute 300 in 5.56 NATO generally rate its build quality highly -- the rifle feels solid and handles a wide range of ammunition without issues. The modular platform makes it easy to swap in optics, grips, or stocks, and the ergonomics get good marks for being comfortable whether you're new to ARs or experienced. The most common gripes are weight (a bit heavier than some comparable rifles in the category) and price (some buyers feel it costs more than the competition). Getting optics zeroed takes some initial effort and may require additional accessories. Aftermarket parts availability for this specific model is more limited than for a standard mil-spec AR, which has come up in a few community threads.