Empty soda cans and beer cans have a built-in target hangar; the pull tab. Tie one end of a string around a short stick and the other around a branch. Put the stick through the pull-tab's hole. Now you'll have a really reactive target! You don't have to cut the can down when it gets too shot up; just take the can down. To change targets merely run the stick back through the pull tab of another can. Run out of cans? Shoot the stick!
Empty tin cans over a stake work pretty well, until you break the stick. Full tin cans only when the food inside is long expired and the can is further than 100 yards. Them suckers really pop when hit. Plastic usually gets recycled instead of shot because of clean-up troubles. A peanut butter jar makes a nice target when laid on end, but when hit it tends to shatter rather badly. When you fill 'em up with water they grenade on impact. And those little bits of plastic are a @%/^$ to find. Which is why you take a BIG cardboard box, turn it on it's side, and put the explosive plastic stuff inside it. You can still make plastic go BANG while containing the mess. Both plastic and cardboard can still be recycled. Just pour out the plastic into a bag. Most of the time you won't find a box big enough, though.
Other favorites include...
Charcoal briquettes, necco wafers, expired chips of any brand, tennis balls (shotgun), golf balls (rifle/pistol), desktop mini-calendar pages, drug ads from any magazine (bonus points for hitting the logo!), out-dated or otherwise useless business cards, worn-out decks of cards (longtime favorite), worn-out non-plastic/rubber cat toys, bookmarks, used post-it notes, coins of all makes (Canadian change!), M&Ms or other candies glued to a backer, those really cheesy "collector's" tins that some food comes in, candles of all makes, metal lids from jars of various sauces, cardboard cereal/snack boxes (empty dufus!), your ex's favorite stuffed toy, those Jack's Head antenna toppers, and a bunch of other stuff I can't think of right now.
