520 ILCS 5/1.2bb

"Single shot" means a gun that is either manufactured or modified to only be capable of holding a total of one round in the magazine and chamber combined. "Single shot" does not include: (a) a rifle in the possession of a person who is also in possession of or in close proximity to a magazine that would allow the rifle to be capable of holding more than one round or (b) a revolver. A gun shall be considered single shot if there is no magazine in the possession of or in close proximity to a hunter in the field and the gun can only hold a total of one round.