Build Your Own AR-15 in 5.7x28mm with CMMG

This is a set of a Barrel and Bolt Carrier Group for the builder who wants all the benefit of the CMMG Radial Delayed Blowback, but also wants to add their own parts to make the Perfect 5.7 Carbine. CMMG's 5.7x28mm Barrel and Bolt Kits are designed to be assembled into a Mk4/mil-spec AR15 upper and work with either a CMMG Mk57 lower receiver or Mk4/AR15 mil-spec lower receiver (when using CMMG 5.7 AR Conversion Magazines).

CMMG AR-15 Barrel/BCG Kit (Matte Black) Specifications and Features:

CMMG 57D88C3
AR-15 Barrel and Bolt Carrier Group
5.7x28mm FN
16.1" 4140CM Barrel
Threaded
Patented Radial Delayed Blowback
CMMG Lifetime Quality Guarantee
Salt Bath Nitride Finish
Matte Black

Includes:
Barrel
Bolt Carrier Group

Fits:
AR-15 Upper Receivers