For what it's worth: I was an Infantryman and the Company Armorer, Aco 2/325AIR 82d Abn. We got the C-mag in for our M249's and I was just as happy as a pig in shit when my Supply Sgt. said get these things out of my way and into your Armsroom. Well the first thing I figured out was that there are not interchangable from M249 to M4 unless you change the tower of the mag. The first trip to the range was a disaster! If the M249 was even a little old and not in perfect spec they would not lock in and or feed. My XO said put those on the self and call Beta Co. I did and they offered to come to us and see what the problem was and while I was on the phone I got them to send me a M4 feed tower. Well the chain of command never let me invite Beta Co and I was soon discharged. However I did get to use the C-mag in my M4 a bit and it failed everytime at the range. The problem that happened most was that the bolt would strip off the Last-Round-Link-Assembly and jam the M4 and render the C-mag usless. I raped other C-mags for there Last-Round-Link-Assemblies but gave up even trying to get the thing to work after I realized that ordering parts to replace raped ones was to much of a pain. It should be noted that the C-mag pouches rock for carrying 30rd mags and the pockets on the side carry a GPS and extra stuff with ease. This was in late 2002 and I hope that GI's have seen some improvement in the C-mag.
Glockdog
Airborne!!