When i was a kid, we use to find leftover weapons/ammunition in the ground left over from WWII, and we used those to play with (the casualties where quite high due to many idiots not knowing how to use guns, and not to point it at your own face/other people/even worse other people with guns) .
Along with those, we found various other interesting stuff like Soviet and German military uniforms and other items like undetonated bombs and shells, shit was fun.
Oh, and if you are wondering where it was, it was in Ukraine, back in the early 90'ies