When we were kids and crackers were allowed we made cannons by squeezing the end of a metal pipe then putting the bunger in with the wick sticking out and then stuffed a ball-bearing in with paper.
It was a great cannon and we wiped out some unsuspecting birds, until the cannon backfired and the face of the person holding the cannon was black.
Luckily he didn't lose an eye.
We also had sky-rocket fights where we aimed a skyrocket at a group across the road. That went well until one landed beside a petrol pump and we were kicked off the street.