I found that I have to have the feeder ramp sparkling shiny when done cleaning. If that ramp is a bit dull it will gum up after some rounds. This will cause the mis feed. As some of the others have mentioned, take the clips apart and clen them. Most guys forget to clean thier clips properly and this can affect the way the bullet is shoved up. I was using Winchester 115 9mm shells for target shooting. They weren't to bad but had some of the issues you talked about. But I went to Remington 115 grain 9mm for my P11 and there was avast improvement. You will find in this forum some suggestions about using a fine dremmel to polish the feeder ramp. But be careful if you don't know what you are doing. Lots of suggestions, but they have helped me.