CMMG 5" Barrel and Bolt Carrier Kit for AR Rifles in 5.7x28MM

CMMG 5" 5.7x28mm Barrel and BCG Kit

In the crafting of a reliable AR pistol or SBR chambered in the nimble 5.7x28mm, CMMG offers an innovative solution with their 5-inch Barrel and Bolt Carrier Group (BCG) Kit. At its core is the patented Radial Delayed Blowback operating system—a marked improvement over traditional direct blowback designs.

The Radial Delayed Blowback mechanism stands apart by effectively reducing both weight within your BCG and felt recoil, ensuring smoother operation without compromising on essential functions like last round bolt hold open. This innovation not only enhances shooting comfort but also maintains reliability under rapid fire scenarios.

This kit is engineered for integration into Mk4/mil-spec AR15 upper assemblies, seamlessly compatible with either a CMMG Mk57 lower receiver or a standard Mk4/AR15 mil-spec lower—provided you employ CMMG's proprietary 5.7 AR Conversion Magazines.

For those seeking to expand their firearm repertoire to include this versatile cartridge while enjoying reduced recoil dynamics, the CMMG Barrel and BCG Kit presents itself as an indispensable component in achieving that ambition with precision engineering at its finest.