I had pretty much the same issue this last week. The primer would not always drop into the primer cup. There was a little play and if I pulled back a hair it would drop. Very annoying. I did all the troubleshooting in the manual and replaced everything including the primer cup slide. Finally I saw in the owners manual on page 45 that the Operating Rod Bracket needs to be 5.625 (5-5/8") from top of the bracket to the top of of the primer feed body. Once I set the distance and aligned everything the primers now come out without any issue. My headache has now gone away and I'm reloading without having to verify there is a primer in the pocket for each bullet. Maybe this will help someone else. Good luck.