i did the same thing you did, exactly! i dunno, i'm thinking maybe my primers might not be seated all the way,so i make an effort to remember this and seat them positively.it seems to have cleared up the problem, but it's just a guess..like you, my kimber ate all the duds without a hiccup...another fellow has the same problem with his glock. i'm using the factory barrel, and don't shoot over a half a box without cleaning if using lead. paying careful attention to fired brass, i get rapid pressures fast, as evidenced by the cases bulging into the feed ramp...hence the need to go to aftermarket barrels to shoot a lot of lead.i was really surprised how fast the pressures rose,now i see where the hoopla about kabooms comes from!so, i didn't help you much, but i got practice typing...