Alright THR's collective expertise...I've been shooting autos for quite some time and I've never been able to figure out why some of my autopistols are unreliable with certain brands of ammunition. I'm talking about identical bullet shapes and weights. The most recent example was just last week. I was shooting my Colt 1911 which has fed everything so far. I stoked it with some PMC 230gr. ball and it choked on every round. Is this problem due to the shape of the rim, since I know some manufacturers use different rim shapes (see an S&B vs. WinnyWhiteBox). Or perhaps the OAL of the round is longer or shorter than others? Any other explainations?