The press (Dillon 650) stopped cold, I couldn't rotate the shell plate. I thought it was a primer not seated all the way or case stuck. But no, the problem was a primer that was not pushed out of the primer pocket. The depriming pin seems to have pushed the top off of the cup, leaving it partially attached. I'm glad it did stay attached because at the next station I would have tried to shove a new primer into the primer pocket that has the outer part of the cup still in it. Here are two pictures of what I'm talking about. What do you think?