1911 Magazine Plastic Base Plate, .45ACP/8RD

I bought three extra magazines for my .45, 1911 Tanker model to go with the two which came with the gun. I had tried Wilson Combat 47Ds in it and they would not seat. The, for some reason would not get past the magazine release inside the grip. I have no such problem with my SDS Government military model, however. These new magazines worked in the gun with no problem, through about 100 rounds. I did experience about five failure to feed overall. My friend, who owns an SDS 1911 Carry model, experienced the same issue, but he was able to use the Wilson Magazines with no problem! Do not understand! I am please with my purchase, thus far!