M91/30 Ukrainian sniper rifles

[Miller Tyme]

Only Tulas have the "CH" marking, but there are some legit examples that dont.
Izhevsks have no special markings to set them apart from standard infantry rifles.
The best way to spot a fake is through education.

Izhevsk do have a special marking to denote them, they have the scope number stamped onto the left side of the barrel shank. The only exception where one might not have this is when they have had a scope swap during refurbishment where they might have ground off the old scope number and never restamped the new one, though this is usually readly discernable.