I bought the 30 rounder from SG, asked the same questions and was told they would fit ALL double stack mags. I got the mag and it DEFINETLY won't work. It will fit in, but sticks halfway in, till you hit the mag release then it will go all the way in, but it goes in too far and the top of the mag hits the slide and wont work. thin metal too and the mag lips bent easily. I compared it to a factory mag and it is slightly different at the top. SG sent me a prepaid postage sticker to return no prob. Made by National.