I friend of mine recently inherited alot of ammo from his wifes grandfather. In the box are alot of rifle cartriges but there is no caliber written on the bottom. They look to be between a 30-06 and a 7mm. The only thing they have stamped on the bottom is W C C above the primer and 5 6 below the primer. Has anyone seen this before. Any help would be appreciated. He's hoping he doesn't have this caliber that way he has an excuse to buy another gun