Get More Rounds and Less Recoil with a 5.7 Build

For your next AR pistol or Short Barrel Rifle build, why not build it out in 5.7x28mm. This gives you more rounds and less recoil. The CMMG AR-15 5.7x28mm barrel and bolt carrier kit features a threaded 8" barrel, chambered in 5.7x28mm and a radial delayed blowback operating bolt carrier. The radial delayed blowback system reduces weight in the BCG and produces less perceived recoil while maintaining critical functions like last round bolt hold open. The 5.7x28mm barrel and bolt kit is designed to for assembling into an AR-15/Mk4 mil-spec upper receiver. The assembled upper is compatible with either a CMMG Mk57 lower receiver, or an AR-15/Mk4 mil-spec lower receiver when using CMMG 5.7 AR conversion magazines.

CMMG AR-15 5.7x28mm Barrel and Bolt Carrier Kit Specifications and Features:

• Item Number: 57D88C3
• 8" Barrel Chambered in 5.7x28mm
• 4140CM Steel
• Radial Delay Blowback Operating Bolt Carrier
• Last Round Bolt Hold Open
• Fit: AR-15/MK4 Mil-Spec Upper Receivers
• Compatible: CMMG Mk57 Lower Receiver
• Compatible: AR-15/Mk4 Mil-Spec Lower Receiver (When Using CMMG 5.7 AR Conversion Magazines)
• Salt Bath Nitride Finish Black

Note:
All NFA Rules Apply.