That’s a standard ak-74 muzzle break, not a silencer. It makes the weapon very controllable in full auto, but definitely NOT any quieter. In Russia, ear plugs you! Caliber is 5.45x39 on that piece.
Sorry, I don’t picture anybody, least of all Russians needing a muzzle brake on a 22cal rifle and the thing doesn’t look at all like any muzzle brake I’ve ever seen, it’s almost certainly one or the new dog whistle type silencers meant to reduce noise levels to non-dangerous levels, the Russians got tired of everybody being hard of hearing after their stints in the military.