Barrel and BCG Kit, 5.7x28mm, 16.1"

The 16.1" 5.7x28mm Barrel and BCG Kit is just the thing for building a carbine length AR in 5.7x28mm using CMMG's patented Radial Delayed Blowback operating system. Unlike typical direct blowback systems, Radial Delayed Blowback not only reduces the weight in your BCG but it results in less felt recoil than a straight blowback system without sacrificing key features like last round bolt hold open. CMMG's 5.7x28mm Barrel and Bolt Kits are designed to be assembled into aMk4/mil-spec AR15 upper and work with either aCMMG Mk57 lower receiver orMk4/AR15 mil-spec lower receiver (when using CMMG 5.7 AR Conversion Magazines).All CMMG products come with our Lifetime Quality Guarantee.