As a small child we lived very near a gun range with a clays section of some sort.
We'd sneak in and find the occasional live 12ga shell on the ground.
Of course they wouldn't fit in our BB guns so we'd lay them on the picnic table and shoot at the primer from "safe" distance of about 10 feet with the BB gun.
We used a LOT of BBs to get there but we did have a few that worked.
That picnic table looked like hell and when my buddy's father found out we were all beaten severely by EVERYONE's parents at some point that summer.