The .25/06 loaded with 115-120 grainers compared to the 270 loaded with 130's is much the same in the field. There is no animal you can take with one, that the other will not replicate.
The .257 Weatherby even loaded with standard bullet construction and lighter weight, such as 100 grains compared to either the .25/06 or .270 Winchester is a superior killer on deer sized game.
The .270 Magnums, either of them, only offer additional performance over the smaller cartridges if you load the heavier 150 or 160 grain bullets and then only on larger elk/moose sized game. (Because of the more difficult angles and heavy timber hunting terrain often encoutered.)
If we go back to deer sized game, they all do the same thing which is introduce the effects of gravity to the game.
The choice you make needs to consider the largest animal you will hunt with the caliber of choice and the terrain most likely to encounter in the extreme.
The .257 Weatherby will chronograph at or near 3700 fps with the 100 grainer and it cannot be described adequately to anyone in print.
If you havn't seen it work, you will never know how deadly and efficient it is and that is before you take the trajectory advantage into consideration.
There has been very little written about the .257 Weatherby over the last 30 years. But, unkless you have lived the life of a barrel or 2 on game, you cannot claim athority to speak of it.
It really is something special.
