Scharfe Patrone M/71 Kal 11mm ( 11x60R).
The use of “11.15” is incorrect, as that is the groove diameter/Bullet diameter…The Rifle is “Kal.11mm”" ( Official German Military designation.).
“11.15” and occasioanlly “11.2” is a Commercial (Civilian )designation.
Now, where exactly was it found? Whilst the M71 cartridge was on generaL issue to the native Troops of the German African Colonies
(“Askari” is a Swahili/Arabic word meaning simply “Soldier” and does not specify any particular type of "soldier ( under Colonial Administration) , but it usually refers to a well-drilled and trained native force, with a proper (German) command structure, Native soldiers and NCOs (Schiumbaschi, etc) with German (White) officers. Mostly the enlistees were Muslims ( Coastal natives) and wore the Red Fez, typical of Turkish (Muslim) soldiers.
The Cartridge was also available from Trading Houses, for Non-military users ( Colonists, Police, Administrators, etc) and the firms of A.Kind (Hamburg)–AKAH, and ALFA supplied large amounts of this cartridge and (surplus) Rifles in this calibre.
Depending on where and when it was used, the ( particular) cartridge could have a “African Connection” of over 30 years ( from 1878 to about 1918).
A single cartridge case, without collateral Archeological finds, narrowing down time and place significance, has little importance.
The Context of the find and the area’s history are all important in defining the importance of this cartridge case find.
In anycase, a well preserved example.