CMMG FourSix Magazine Features The CMMG FourSix magazine is engineered exclusively to feed the 4.6x30mm cartridge delivering reliable feeding across a substantial 40-round capacity. Its polymer body is molded to closely match the exterior dimensions of a common 30-round 5.56mm AR magazine so it fits standard AR-15 magazine wells without modification. This close dimensional match means shooters can carry and stage FourSix magazines the same way they already handle their other AR-pattern mags. Reliable feed lips and a durable follower keep rounds feeding consistently from a full magazine down to the last round. Finished in black polymer the FourSix magazine matches the look of most AR-15 hardware and resists the wear that comes with repeated loading and unloading. It is designed to pair with any AR-15 lower receiver giving builders flexibility when assembling a dedicated 4.6x30mm upper. The 40-round capacity gives shooters extended range time between reloads compared to smaller-capacity options. Built by CMMG specifically for their FourSix platform this magazine is a direct purpose-matched feeding solution for 4.6x30mm shooters. CMMG FourSix Specifications Brand: CMMG Model: FourSix Caliber: 4.6x30mm Capacity: 40 Rounds Material: Polymer Color: Black Fits: CMMG Mk9 AR-15 Available At: GrabAGun