Mal H. You're quite right. I've had more than a few go off while seating them in using the Lee dies. (not the ones that screw in a press, but the ones you use with a hammer) I finally worked up a cool way to use those dies and eliminate most of the hammering.
I found an old Stanley press that was used to convert a hand drill into sort of a drill press. Now I use the hammer to remove the fired primer and remove the case from the die. Ever other function uses the old drill press goodie.
To be really honest about it, those dies are just about retired. I keep looking for old Lyman tong tool dies, and snap them up every time I come across one that I don't have for a caliber I do have. (did that make sense???)
I shoot a lot of cast lead, and I seem to get my most accurate loads using that old tong tool.
If it wasn't for the shell holder being in the way, you could even remove the squashed primer with it easily and safely. Every once in a while a primer will flip over and go in bass ackwards. The tong tool removes them gently enough that they are still useable.
Another good point about those Lyman tong tools. When loading up cartridges for my 30-30's, it's slow and relaxing. It's almost like being transported back in time, doing it the old fashioned way. I like it.
Paul B.