I was shooting armor piercing rounds from a 50 at a tank. Had one bounce back and hit my LT in the leg. He walked over and said "Ya need to watch where ya shooting that thing" and dropped the bullet into my hand. Still have it...somewheres.
Was shooting 73mm RR (anybody else remember those?) from the prone on range 44 back in 1980. Hit the road-wheel on a M113 hulk at about 150yds.
On impact, the round detonated and the aluminum fuze assembly came straight back at me and impacted the sand right under my chin. I didn't even have time to shit myself, it happened so fast.
Dug it out of the dirt. It was a light, blast-formed lozenge about as big around as a silver dollar and as thick as my finger. Had the green paint from the road-wheel impressed into the front like it had been painted there. Carried it around in my pocket as a good luck piece for years. Still got it at home somewhere.