My take would be you can't go wrong with the standard 6.5-06.
I have had and killed game with the 6.5x57, 6.5 rem mag in a 98 mauser to take advantage of the longer 140's and the case capacity, as well as 6.5x284. I have also had and been very fond of the 6.5 win mag.
I finally sold all but the 6.5-06, which was originally a .256 newton and couldn't be happier, easy to make brass from 25/06 or 270 brass.
With a decent 140 grain bullet you can't go wrong.
I have had and killed game with the 6.5x57, 6.5 rem mag in a 98 mauser to take advantage of the longer 140's and the case capacity, as well as 6.5x284. I have also had and been very fond of the 6.5 win mag.
I finally sold all but the 6.5-06, which was originally a .256 newton and couldn't be happier, easy to make brass from 25/06 or 270 brass.
With a decent 140 grain bullet you can't go wrong.