Indeed the .25/06 is an excellent cartridge.
For me though, it's an "in between" -.25
I've got two .257Roberts and a .257WbyMag.
The Roberts with handloads are indistinguishable from the .25/06 and the .257Wby though on paper somewhat "more", again isn't really that much better.
Don't let the "nay sayers" convince you that the ballistic coefficient of the .25's are "too low". Also, don't let the 6.5 clubbers convince you that the sectional densities are too low.
There isn't much a .25/06 can't do with the correct bullet.
That said, I've got essentially one load for all big game for my .257 "Bobs". It's a 117-120gr bullet over 45.0gr of IMR4831. This more or less duplicates the factory .25/06 loads at 3,000fps. I've killed dozens of deer, several pigs, and other assorted game with this load or equivalent.
One aquaintaince knows a female guide in Canada that routinely uses a .25/06 w/Nosler 120's as a back-up rifle for Moose. She's also downed a number of grizzly bears with it too. Personnally though, the .25's wouldn't be my choice for that task. For that, I've got a .338/06........
The difference in terminal performance between my .257's, 7mm's, .30's, and .338's isn't really that great. Bullet weight and constuction is the determinant.
For anything smaller than a Moose, the .25/06 will work!
Shot placement, shot placement, shotplacement.............
BTW: for loooong range prararie dog shooting, it dosent get any better than the .25/06 (.257Roberts) than the 85gr Nosler Ballistic Tip at 3,400-3,600fps. Also, I took a fat Muley doe in Montana in '93 at 378yds with the Nosler 85gr B.T. Broke the spine and exited...... Klled over 50 prararie dogs with same load two days later..... Some at over 400yds.
nuff said !