Looks like KV-1 of 1942 production series with cast turret. But for some reason the gun is F-34 and not ZIS-5.

Gilgamesh404 said:

Looks like KV-1 of 1942 production series with cast turret. But for some reason the gun is F-34 and not ZIS-5.

I realize this is a bit late, but that happened quite a bit. The Russians were able to produce more of the new turrets than the new guns at first (due to the relocation of their industry eastwards,) so a lot of the new model T-34s and KV-1s were sent to the front with older guns in their turrets.