I feel your pain! In general, I have an easier time running large primers, for .45, than small primers, for .38 Super and .40 cal. Having had several conversations with folks at Dillon, I've finally gotten to where I can get through fifty or sixty rounds, without a primer problem! That's not a particularly good average but much better. Also, Winchester primers seem slightly larger and easier to shear than, say, either Remington or Federal primers. The suggestion regarding use of a smoother, more subtle technique, is also good. You should be able to feel a primer problem before it jams you up. Pulling a case out of Station 2, when you get a wrong feel, saves lots of powder mess and time. Also, I don't fling nearly as much powder around as I used to. I loaded my first batch in mid-January but have run about 10k since. Doesn't make me an expert but I'm clearly better than I was. You will improve, despite or because of the frustration. By the way, I've got an electric primer filler I'd be happy to sell you! Just added to the aggravation.