CMMG Mk4 AR-15 5.7x28mm 10 Round Magazine

A 10-round polymer magazine for CMMG 5.7x28mm Radial Delayed Blowback uppers, used in a Mk4/Mil-Spec AR15 lower. Redesigned with a new stylized texture grip, 5.7x28mm engraving on the sides and upgraded feed lips. It keeps last-round bolt hold-open and uses a standard carbine buffer and action spring, with no tools required. Covered by CMMG's Lifetime Quality Guarantee.