Stijn, my P90 doesn't like leadheads, I have to shoot jacketed rounds, you may have the same issue. I determined that the feed ramp on mine is too steep and the lead digs into the ramp and hangs up just long enough to not allow the slide to come all the way down to a closed position. (It happened to Dave) So I shoot JHP double deep with some "extra" powder. They never jam and they always go down range.
