Ammo
Tin Foil Plugs: Good ammo, takes time to make, but is reuseable, can scratch the barrel.
Oranges: BAD, VERY BAD. DON'T USE!
Apples: Use Crab Apples, abundant source of ammo. If you have a tree that is.
Potato: Mmm, baked potato.
Golf Ball: Wrap it in paper for a seal.
Wood plugs, reuseable.