Does it have to be air that transfers the energy? Can you use the air to power a piston that physically smacks into the can, without shooting off itself? I can use a piston, but I have to smack the can with the air. I saw a video, can I put in a pneumatic gun a barrel like the one of the first gun ...

Thanks for your answers.
I saw a video on youtube, do you think this is strong enough? or a pneumatic cannon is more powerful?

Hi everybody, I am going to do a school project related to air cannons and a have a noob question that i didn't found with the search function. I want to do a cannon but it has to shoot only air (projectiles are not allowed) and it has to throw some aluminum cans at different distances, my question ...