I'm only half joking - I once met a Japanese guy whose job during WWII had been to test torpedo fuzes with a hammer. I thought he was joking at first but he showed me pictures (it had been in the basement of the very building I was working in at the time). I asked him if anybody ever got hurt and he shrugged nonchalantly and said "oh, sure, all the time."
I haven't complained about any of my jobs since...
The fuses in Japanese grenades in WWII were lit by pulling the pin, inverting the grenade, and slamming the top of the grenade on something hard, usually the grenadiers helmet. Their grenade fuses were even more unreliable than ours were, and they occasionally detonated on ignition. Bummer.