CMMG Rifle Magazine, 22 LR, 10 Rounds, Fits CMMG MK4/AR15, Flat Dark Earth 22AFC77-FDE Featuring an impact-resistant polymer tube with a shock-resistant floor plate and compatible with any standard AR-15 lower receiver and converted uppers, the CMMG MK4 / AR15 .22LR 10-Round Magazine offers smooth and consistent operation in virtually any target shooting or training application.