There are some questions on the tool cartridge shown on the pics.
It’s said, that it’s a - maybe unknown - german trial-caliber 20x135, but the known ones have other cartridge case-proportions. The dimensions are really near the post-war 20x139.
It’s said, that the cartridge case is made of brass.
In my opinion, the headstamp could be a fake: P , Ex , [eagle]WaA 75, 34
Did someone got a similar cartridge and knows the right caliber and the origin?
All answers and - hopefully - declaring pics are very wellcome.
Thanks for support.