Only experienced it once.... Many years ago with one of the old Lee Loaders tapping it in to seat the primer on a .303 British case. Didn't get hurt but decided I didn't want that happening again. Nowadays I have a small single stage Lee press mostly used for depriming and priming. Do the priming with a Lee Ram-Prime because I like the feel of it as you are seating the primer. Used to use a Lee hand held auto-prime also but eventually started doing it all with the ram-prime. No more slamming for me.
