25 mm?

What is it ?

It seems fired.

Thanks for your help.


Symbol on Back of shell is one of the Russian Factories (?Soviet)…Looks like Barnaul??

23mm ( either 23x115 Aircraft MG or 23x??? Anti-Aircraft Gun.)


Symbol on the back looks like a duplicate 6 or 9

there is another 6 on the side.


Yves, very interesting projectile, I don’t know what it is. However, I can’t avoid thinking it couldn’t be for the “Canon à tir rapide de 24 m/m” of 1899. Were any of these cases ever reported to exist?

As per the marks of the lands on the driving band I would not say that it was fired but rather pressed into a barrel section as the lands did not leave the impressions over the full width.

Definately nothing for Soviet 23x115 or 23x152B.