I have a 7x57 Ruger #1 which has become my favorite rifle. I have taken many deer and one black bear with it. It will consistently shoot 1 inch groups at 100 yards with my handloaded 140 gr. bullets. It is accurate, has plenty of punch and very reasonable recoil. It has been my primary hunting rifle for about 12-15 years. I have never used any of the 6.5's. Basically it boils down to picking whatever rifle in either caliber you prefer. Perhaps leaning to the 7mm if going after any bigger game.