I knew some idiots who found an M79 round near Camp Williams in Utah. They put it in the campfire to see what would happen. They all survived but got various amounts of shrapnel and hearing loss. Darwin Award Runner-Ups.
When I was a USN HM3 on Camp Pendleton back in 1981, we had an emergency run at the north end of the base at around 1 AM... two Marines were drunk and had ventured out into the impact area of a range used for M79/M203 training. One of them found an unexploded 40mm fragmentation round and picked it up. It took his arm off just below the elbow, as well as peppered his face and chest with shrapnel. Missed his eyes, but he spent the next few months in and out of long, painful surgeries removing all those little bits of metal.