Re: 257 Wby vs. 264 Win Mag
I've had them both and the 264 is the winner in this shootout.
There are MUCH better bullets with higher BCs available for the 6.5 (264) then the 257 if you are a handloader.
Being as this is a longrange forum and I presume most of you are are longrange hunters, I would much rather use a 140 to 155 gr high BC bullet compared to the little 100 gr (with low BC) that is popular for the 25 caliber rifles. There are a bit heavier 25s but, not to many.
Ballisticly the 264 wins, no doubt about it.
Run the numbers on your ballistics programs and check the energy levels of both at all ranges.