20mm projectile - German or British ?

[ammofo]

Hi all, I've just purchased a mixed lot of ammo with some British and German projectiles loose and mixed up. Sorting out the others I'm left with this one and wondered if it's from a German 20mm flak or a British 20mm Cannon. It doesn't have any markings that I can see......any thoughts welcome !!

 

[pzgr40/42]

It's certainly not German FlaK.
It might be 20x110 Oerlikon ... perhaps Swiss.

 

[ammofo]

Well that could fit nicely in my British /|\ 1941 Oerlikon Case - it certainly looks the part !!