I was convinced it was a seating pressure problem until your last post on page one. If you have not been cleaning out the rear pocket of your breechplug with a drill bit, that is almost certainly your problem. You will be astounded at how much fouling you get out and how hard it is. You will also be surprised at how far up the breechplug the drillbit will go. I don't use a drill, just grab the drillbit with a pair of pliers and turn the breechblug by hand.