Robert: do not shoot the Korean 06 in your Garand. There have been reports of Garands coming aprt after firing that stuff. There was a warning about the Korean surplus ammo, on this site, within the past year.
I am not certain about the Greek ammo and do not recall warnings about that stuff. I know that Greek 303 British ammo is pretty good stuff but haven't heard about the 30-06.
If you have Korean surplus ammo I would use it for components and not risk your Garand. JMTCW. Mikey.