Hi All i have had this case for more than 35 years and i believe it to be a 13cm German WW1 case the measurements are 135X705 the head stamp is PATRONENFABRIK KARLSRUHE DATED 1918, the thing that puzzles me is it has 12 holes in the top part of the case is it for pining in the different charges used or has someone tried to make something out of it.
Cheers
Andy
Cheers
Andy