Identifying (German 20mm??) steel casing

[PanzerSchokolade]

Hello,

With a metal detector, I found a rusted part of a casing. I would like to know what type of munition this used to be. It has a similar diameter as 20mm Hispano, and since it is made out of steel, I think it is a German 20mm casing.



There is a headstamp placed on the primer of the shell, which I have not seen before. The headstamp is: "P2 exw 306"


The headstamp also seems to confirm that it should be German, since the P-code is often used by them. So, if anyone has an idea which type this casing could be, please let me know! Thank you in advance for your time.

[llegion]

It most probably is the remains of a casing from a 20mm FlaK cannon. exw on the primer is the name of the factory (Metallwerke Holleischen, Kreis Mies, Sudeten Germany).