I recently have been having an issue where I will load a random number of cases without a problem, then will have several primers fall from the magazine tube, into the small raceway in the primer slide assembly and they will eventually fall out the back of the primer slide or the bottom of the press and jam it up.  I have already replaced the primer pin return spring, as I found that cracked and the magazine orfice, which was slightly deformed.  I thought that I was good to go, loaded probably 25 cases and primers started falling out of the press again.  I've cleaned the primer slide, the housing and roller.  Checked the primer punch, cleaned it and the cup and checked the height.  Now, I also removed the primer pin (an older steel model- not Delrin like the newer ones) and cleaned it and the hole, loaded about 25 more rounds without any problems. Hopefully that is the end of my problem, but I guess that I'll see.  Has anyone had a problem like this and can shed some light on what's going on?  I'm not sure if the pin was hanging up or what was going on.