Well, if you were to ask me then I'd tell you to buy a gun that is:
- Light enough to carry all day.
- Feels like it was molded to you. Good balance, shape, and profile for you.
- Accurate.
- Chambered in .308 or .30/06
Yes, I said .308 or .30/06
Here's why: You don't need nothin bigger. Plain and simple as that. If you buy a .308, you will be able to afford to shoot and practice at the range. By being able to practice more at the range, you will know your rifle, scope, ammo, and rangefinder a lot better. How much better? A lot. Any old Joe Blow can throw the dot of a rangefinder on something and tell you how far away it is. But only someone who spends ample amount of time practicing their shots will be able to tell you how their particular rifle and ammunition will perform at that distance; how far the bullet drop is, how the wind will affect the flight path of the bullet, etc. The same reasons could be used in support of a .30/06...
Not so true of the latest and greatest 7mm/.300/.338 super-dead killin, whizzum faster than nuttin else, shoots so far you can't even see the target, uber-super-ultra-powerful blah blah blah magnum...
At around half the cost of similar premium hunting ammo chambered in the super-duper magnums, the .308 is a much wiser choice IMO. I would have much more confidence with a .308 that I had spent countless hours shooting than with a super-duper magnum that I only shot a few times because of the recoil, muzzle flash, noise, and absurd cost of the ammo.
YMMV, but at ranges <350yds, I'll take the .308 for any animal on the continent. And yes, that includes brown bear. And I doubt very seriously that even half the people that own a super-duper magnum have ever shot it past 300yds, much less the 1000yds capability that they so readily flaunt. The shooter makes the shot, not the cartridge.
Speed does not kill, nor does it directly correlate to killing power. .308 and .30/06 are plenty of gun for HUNTING. Long-range SHOOTING at animals is another story entirely.