I have went a few rounds with my LNL AP priming system in the years that I have owned it, which it is one of the early production presses. A friend of mine saw my progressive and bought one of his own and quickly started having priming problems also. He figured it out if he filed the bottom of the slide shoe so that the machined groove extends all the way to the end it can't hang up on the primer seating punch. I did this to mine and, voila! It works like it should now. Before I did this alteration I was constanly having to adjust the punch. First down so that it wouldn't hang up on the shoe, then after I loaded some rounds it would get so that it wouldn't seat the primers deep enough and then I would adjust it the other way. Now it just works ;-)

cool.. pic?