Here's my thoughts... it is a good deer and antelope gun I wouldn't use it on elk I think it is too light. Elk are tough animals if you want to put one's nose in the dirt you need bigger. It will kill an Elk sure and lots have been killed with it no doubt, but so will a .22lr. If you don't handload that's fine. I like the 110 Accubonds others have mentioned I'm sure someone offers them in factory loads. 25-06 isn't going to be as fast as the .257 but I don't think a deer will notice the difference.

Long range means different things to different people so when the cartridge first came out 40 years or something before it was standardized in the late 1960's it was billed as a long range flat shooting cartridge that meant 3-400 yards shots like a laser beam. That was long range in a time when a lot of people were still shooting a 30-30, .35 Rem, etc.. Think... nobody every heard of a 7mm Mag back then and at some point after that there was a crazy guy named Roy Weatherby running around in the 1940's with something he called a .257 Weatherby Magnum that some turned their nose up at, others got on board with, and yet others though it was a barrel burner glorified varmint rifle. After WWII the market was flooded with surplus guns for decades. .25-06 was a flat shooter. And still is but it isn't a 500+ yard gun.

So what you are thinking about buying I think will make a great deer rifle. Not quite a .257 but just a good solid cartridge. Looking at the ballistic tables you'll see that you can easily shoot just over 300 yards with scope adjustment or Kentucky windage. That's far enough for most. Sure I can shoot further myself, but I don't have much trouble getting within 300 yards of a deer if I can see one that far.