We used to shoot bottle rockets out of our bbGuns.
We'd light'em and then shoot em at a target... the fuse would ignite the propellent and that wissel would indicate a successful firing of the mains that drive the mini-missile. We would get some incredible distance off of them.
(Drop the stick portion of the BR into the barrel of the bbgun. COPY CATS NOT RECOMMENDED: This was done by professional 15 year old trouble makers who had no idea of the danger involved. Do not attempt.)