Smithsonian. Uh, oh, MAGAZINES. Ok, I got it. As pointed out before, the cheapest are the best. I'm getting to where when I bring them home, insert a few rounds and slap them into the AR to see if they'll feed properly and if they don't, I can usually "adjust" them with a pair of needle nosed pliers and get them to work. I've bought only 1 mag that I couldn't get to work. (My Panther shorty seems to be fussier about mags than my Colt)