Does someone know weight difference between 6.5x54 and 7x57 full stocked Mannlicher Schönauer?

I am planning buy one these great rifles. It seems that 6.5x54 is more common in used market than 7x57.

7x57 would be more versatile in my hunting use, I could use it in moose hunting too. But 6.5x54 is suitable to any other game what I hunt.

Any recommendations of production years what to look, pre WW2?