If you look on the Illinois State Police website regarding our FOID cards and forearms regulations in Illinois, there is a definition of a firearm and ammo as regulated by the FOID law. It goes something like - anything that discharges a projectile of over .17 caliber powered by expanding gas or escaping gas. I may have oversimplified the definition or screwed it up somewhat, but I think that's pretty close.
One day I was reminiscing about my childhoos near Austin and Roosevelt (GrimJim will know eher that is at), and I remember how much fun I used to have with a "Bean blower" and a box of dried whole peas. I got some very thick plastic soda straws (without a waiting period or ID check) and some peas and had a ball. Filled my mouth and shot them on full auto. Gave one to my 9 year old nephew along with his own box of peas too. Sometime afterward I read the definitions and regs . OH, OH!
Am I in deep doo-doo?