Very true....however magazines (in the Army - the Marines can't be that much different) generally go along these lines.....nasty, thrashed GI mags you draw from Supply or the Arms room and turn in when you leave the unit, actual issued PMags, or personally bought PMags. There are hundreds of thousands, if not millions, of these magazines in the system. They're there, and they became so awesomely popular, b/c they were leaps and bounds better than the aluminum issued mags. IMO, PMag is synonymous with functioning magazine.
NickB's post is excellent.

