What cartridge markings does the rifle carry, I presume it would be 275 Rigby and not 7mm Mauser. Seems to be a lot of confusion about these two cartridges, some information and rifle owners suggesting they were one and the same and others not so. Both the 7mm Mauser (7x57) and the 275 Rigby ammo were loaded with the 173gr bullet in early years, the 175gr coming later for the 7x57.