CW +1
Of course, it is the bigger bullet, better expansion ratio, better SD and so on. Oh, as posted above, I get over 2800fps out of my 18" 8x57 with 150gr Sierras, for flat out "highest velocity" in my 8x57. Dad's 20" 30-06 yields the same velocity as my 22" Remington 30-06. They give 2900fps with 150gr Hornadys. I hardly ever use 150's in either caliber as there are better weights for what I want to accomplish. I have witnessed my 200gr Noslers at around 2400fps outperform my Dad's 20" 30-06 with 180gr Noslers at over 2600fps on Elk at over 250yards - Dad witnessed it, also. He was astonished at the smackdown I put on that Elk.
Elmer Keith knew the value of "big for caliber" bullets for penetration; and the bigger the better. He pretty much had first hand experience to draw from when he made statements of any kind. Made it right for him, not necessarily for everyone else, though I do mostly agree with him.
Most differences in calibers of this class are simply on paper. Which is best becomes which do you prefer as there is so little difference in reality. What I've witnessed sways my preference for the 8x57. I doubt my Dad would consider swapping his '06 for any 8mm, even though he felt the 8x57 would be a great caliber for me when he put it together. I was never impressed with the 8x57 until I got to Wyoming and really put it to work. It easily could be the "only" rifle in the rack, but then again, so could the 30-06. Lucky for me, they are simply "cabinet mates", among others. As an aside, I wouldn't consider rechambering my 8x57, but that Remington is becoming my 35Whelen - to be off on another handloading adventure.
This is a great thread with a lot of good input and thought generation. I salute the contributors!
Regards,
Sweetwater