§ 1. . . . for the purpose of this Act the term “machine gun” applies to and include all firearms commonly known as machine rifles, machine guns and sub-machine guns of any caliber whatsoever, capable of automatically discharging more than eight cartridges successively without reloading, in which the ammunition is fed to such gun from or by means of clips, disks, belts, or other separable mechanical device. § 2. It is unlawful for any person to sell, keep or offer for sale, loan or give away, purchase, possess, carry or transport any machine gun within this State, except that (exceptions for law enforcement, military, war relics, museums, guards, messengers) . . . .