I have a 1911 magazine that is very difficult to insert into my gun when it is fully loaded with 8 rounds. I have to really push it in hard or slap it in hard to make it lock into place. If I take out one round down to 7, it is perfectly easy to load. All my other mags are also easy to load even if they are fully loaded with max amount of bullets. This mag I am having problem with is a new one I just bought. Any ideas? My gun is a Kimber 1911 and the problem mag is also a Kimber.

gotta be just a bad mag.  i've got 7 round kimber, 8 round kimber and 10 round chip mccormick mags and hadn't any trouble loading them into either of my two kimbers or my springfield gi..