Gentlemen, this is my first post, however I feel that I am qualified to comment on catapult matters, firstly ammunition, a lady neighbour told me she used ice cubes to discourage cats from using her garden as a toilet, hmm a bit inconvenient when required at short notice but disapear without trace, my own choice of biodegradeable ammo is the humble Aniseed ball ( an old fashioned English sweet ) don't know if these are available worldwide, nice size, hard, shatter on impact with hard surfaces, food quality so wont damage the environment & you can eat them! what more can you ask? One day my best friend in the whole world brought a Barnett Black Widow catapult because he didn't think it was accurate, after I smashed 3 aniseed balls one above the other on a clothes post 90 feet away he concluded that it wasn't the catapult that was at fault.
Where I worked at the time we had a sort of catapult club & during the dinner hour we would go through the car park to a river which ran past the factory, carefully selecting useful pebbles from the drainage channels alongside, we then walked along the river bank assaulting targets of opportunity using a mixture of pebbles,glass marbles, ball bearings & my own particular favourite to be to be used only against metal containers & rogue bull elephants, spent carbide throw away lathe tool tips! we would then surface at the other end of the factory, & clock in satisfied with our target practice. There is more to discuss but right now dinner calls.