Citation(s) from the GunPolicy.org literature library
US Army. 2006 ‘Acquisition and Possession of Privately Owned Firearms in Germany.’ US Army Family, Morale, Welfare and Recreation / FMWR. Heidelberg: United States Military Command Europe. 3 January
Acquisition and possession of Privately Owned Firearms (POF) by uniformed or civilian members of the US Forces in Germany is governed by the German Weapons Law (and US Forces Regulations) …
In order to legally possess POF in Germany you must obtain a German Weapons Possession Card (Waffenbesitzkarte/WBK). Such a card is NOT a concealed or a non-concealed weapons permit (meaning it is not a permit to carry POF around with you while shopping, etc.).
A WBK is a permit that allows you to purchase certain POF, use them on ranges (or in the case of hunters, while hunting), store them at home (in a weapons safe meeting German security specifications), and transport them from home, in the trunk of your car (POF kept in a case and separate from ammo) to a range, hunting area, or gun smith. It does not permit you to have with you or even carry POF inside the vehicle while driving around, going shopping, etc.
If you intend to use only loaner guns from the Hunting, Fishing & Sport Shooting Facilities to shoot at their ranges you do not need a permit (WBK).
If you want to purchase your own POF or bring POF you own from the US into Germany you will have to be a sport shooter or a hunter and be in possession of a WBK before you take control of the weapon in Germany. This WBK is only a valid document in Germany.