Guys, I found a thread under the Vintage AR section in which the history of the magazine for the AR is discussed. There are two people on that thread that have pretty much summed it up… Patrick Sweeny and Larry Vickers… Check it out here is the link. If anything its a nice quick history from a couple of real SMEs
I like to consider PMAGS, Lancers, and Tangodown mags as product improved mags. Especially the PMAG considering its in such wide usage.
One things that makes them so much more reliable is that polymer is more durable and thy have a constant internal curve designed for the taper of the 5.56.
Thanks, good link.