I've lived in IL my whole life and have never heard of the 45cal rule where did you find that?.
It states it right in the "Illinois digest of hunting and trapping"
"For shotguns and muzzleloading firearms, the
minimum size of the projectile shall be .45 caliber.
A wad or sleeve is not considered a projectile
or a part of the projectile."
I had always heard that sabot's were illegal to hunt deer with but could not for the life of me figured out why they sold them here if they were. Well now I know the whole story and have decided what to do. I will take Tim's information (like usual, its never failed me yet) and buy a box of the Hornady SST's, Buckhammers, Coppersolids, and a box of Hastings. Shoot them all and see what happens.
Thanks for all who replied, not sure where you all get your endless pit of information about things I can never find on the internet, but I'm not sure what I would do without it. Thanks!