I've heard many complaints about this. The pistol was originally designed for a 7 round mag. I know this is beating a dead horse but it bears repeating. I use CM 7 round mags and Wolff springs and Tripp 7 round mags. There are hundreds of posts about mags and springs for the 1911 and I don';t know how many I've run across that have problems not only seating a full 8 round mag but problems feeding as well.

I have a few Wilson ETM mags that was designed for 8 rounds...not seven and the attempt to squeeze 8 rounds in them by shortening the tail of the follower. Other than that, I stick to the 7 round mags.

You might ought to mull over this article by someone who speaks with great knowledge about this.

The M1911 Pistols Organization Forums Site - Magazine Burps

http://forum.m1911.org/showthread.php?t=44064