was shooting my(then) newly scoped SKS with a friend, he began to get upset that i was outshooting him, so he kept suggesting smaller and smaller targets.
"bet you can't hit a bottlecap" at 50 yards this was no trouble, put two holes in it quickly
"bet you can't hit a screw!!" he proceeded to drill a 3" drywall screw vertically into the top of the homemade target stand i had constructed, leaving about 1.5" of the screw exposed
"can't see it from here" i said
he stuck a white note card behind it to give contrast and my first shot blew the screw in half
have also shot at and hit:
golf balls
empty shell casings/shotgun shell hulls
small ceramic figurines from the dollar store
old hard drives
capacitors - makes confetti
circuit boards - multiple tiny targets on each one
ping pong balls
try to shoot the nock off an arrow stuck in the ground vertically
rebar stuck in the ground vertically
coins
phone books
any piece of tech that has bricked
hard boiled eggs
vacuum cleaner - dont ask
steel doors are very fun to shoot with a 12ga
cut down saplings with as few shots as possible(small calibre)
shooting water balloons out of the air is quite entertaining
primers on live shotgun shells or rimfire rounds with a pellet gun
found out years ago that you can drop a finishing nail down the barrel of a cocked/loaded .177 cal pellet rifle and it will surprise you what this will penetrate; ammo cans, brass door knob, steel door, cinder block/brick. once pinned a squirrel to a tree in this fashion, he felt no pain, it was a headshot