The journey begins with the (Universal Self-loading Carbine), which is the factory-legal civilian version of the UMP.
For a civilian looking to acquire a 9mm Heckler & Koch UMP, the "story" is one of patience and technical transformation. Because the true full-auto UMP was introduced in 1999—well after the 1986 ban on newly manufactured machine guns for civilians—you cannot simply buy an original factory UMP 9mm for personal use.
To turn that USC into a 9mm UMP, you must perform a caliber and furniture conversion. H&K USC: Civilian Version of the UMP Submachine Gun
Instead, enthusiasts follow a well-traveled path of converting a legal civilian carbine into a faithful UMP clone. 1. The Foundation: The HK USC