Years ago
I primed a 20 ga. case and pushed the mouth into a bar of soap. At 20paces I shot it with my air rifle. That primer flew across the room and struck me on the right thigh...2" more left and I would have been a lot more sorry. It really smarted, and when I pulled down my jeans I found a red welt imprint exactly like the base of the primer. VERY dumb.
I still deprime live primers in my single stage press when necessary, but I do it with slow, gentle pressure and have never had a problem. But I have a lot of respect for them, I'll tell ya.