In Chicago/Riverdale(Cook County) there are local ordinances against owning "assault-style" weapons, yet there are multiple firearms dealers in these cities/villages.
Does the banning of firearms not apply to the sellers?
Does anyone who buys a weapon from here and walks out of the store immediately commit a crime based on ownership alone?
Chicago Ordinace Wikipedia Reference
It shall be unlawful for a person to import, sell, manufacture, transfer, or possess an assault weapon.
Definition Of Assault Weapon Cook County
Many places in cook county sell rifles with muzzle brakes and telescoping stocks which makes a weapon classified as an assault rifle.
Eagle Shooting Range in Cook County,IL sells what cook county classifies as assault weapons.
If you take a look at the weapons on the sale floor here here you will see rifles with telescoping stocks and muzzle brakes.
I am a local to this area, there are many different weapons that meet the requirement to be classified as an "assault weapon" (based on the definition).
They are open about these sales too, if you were to call up this store and ask them do they sell a Springfield Saint Edge, they will tell you yes.