I had some fail to fire problems when I first started using Wolf primers. Problem was that I was not seating them firm enough. You have got to really add more force to seat them. Their cup is harder and tougher to form to the primer pocket. I also noticed that the anvil sits up just a little more than other primers and with my Lee hand primer I can feel the anvil hit bottom and then add more pressure and feel the cup hit bottom and compress the anvil against the priming pellet properly. Since finding this I have not had a single problem with Wolf primers.