Statjunk, I do not know what you are loading but a primer that is protruding can fire when chambered in a slide action or auto loader, it has happened, if a primer is seated after the cartridge is loaded, powder can trickle through the flash hole and fill the area above the primer, this could prevent the primer from seating and an attempt to seat the primer could crush the anvil, some shell holders that are designed to load auto loader type cases, 9MM, do not have a slot or relief for the primer (single stage presses), this prevents a high primer from being slid into the shell holder, the case will stop at the edge, this should tell the hand loader there is something wrong, once the high primer (unseated) is identified (before powder and bullet) the primer can be seated or problem corrected.

f. guffey