US Marines Corp. authorized use of Gen M3 PMAG for combat use. USMC will also use US Army's EPM(Enhanced Performance Magazines), but for training purpose only.
PMAGS were prohibited from use 4 years ago when USMC found out it doesn't fit with M27 IAR. After redesign and testing, it is now good to go with the USMC. Also authorized is the new Medium Coyote Tan.
From: Soldier Systems