[dhoward]

Don't know if this helps or not, but my technique has always been to pause slightly during the primer seating. Primer seating, and pocket cleaning are two of the most important steps when manufacturing reliable match rounds, and I find myself really trying to 'feel' the primer seat. As I make it a distinct effort and motion, I can always feel when a primer is cocked. Doesn't happen often, but it does occasionally. Never had a stack go off.
Would like to have seen it from afar.
+10 on Dillon, and their support. It's outstanding.
I have had good success with C-H progressives too...