Powder copper canister

I have this canister that I bought there is a long time ago in France (Vosges)… but I can’t find any information about it ?
It’s made in copper with some grey paint remaining

, approximately lenght : 22 cm , diameter : 14 cm
There is also an inside small cylinder mark with a hole at his center which is approximately 9,5cm of diameter …
Outside you can clearly see a mark of something ?

It looks a bit like a 10,5cm wehrmacht m18 kanon shell but I don’t think this is it…or a worked shell ?
Is it a container ?

This should probably be posted in the General Ammunition part of the forum instead of questions about the forum

Sorry I’ll post it in the right place :)