Hi Stuffy!
If you copy and post the headstamp markings, that should help to positively identify the cartridge and country of origin.
The former Soviet Union (Russia, Ukraine, Latvia, Armenia, etc.) and it's former client states (Communist Bloc) characteristically make their small arms ammunition with lacquer-coated steel cases.
Sometimes the cases are simply copper-washed, and lacquered, and sometimes they are gray or brown-lacquer directly on the steel.
Your cartridges with the plastic bullet filler sound Russia, probably Wolfe brand. They are widely available and considered excellent pinking ammo.
HTH
John