Soviet 57mm casing?

[Don D.]

I believe this is a Soviet 57mm casing. What gun would it have been for? How do you read the markings?
Thanks in advance.

[klarkon]

https://en.wikipedia.org/wiki/AZP_S-60

https://en.wikipedia.org/wiki/AK-257

http://russianammo.org/Russian_Ammun...e_57mm.html#27

176 - manufacturer's code Tula ammo plant, CA - inspector's mark, 70 - series, K - year of production 1958.

[Don D.]

Thanks for the information and the links.