Varmints through Elk! Thats a very wide range of use for one caliber!
I agree. I'm not a big advocate of the one gun for everything concept either. Anything Ideal for elk is going to be pretty heavy for prairie dogs and anything ideal for small varmints is going to be pretty light for elk. If you try to split the difference right down the middle you end up with something that isn't ideal for either end of the spectrum. What game exists where you live and what are you going to hunt "most". Buy a gun and caliber based on that. For example, I wouldn't spend the next 10 years shooting ground hogs with a 300 win mag because one day I dreamed of going on an elk hunt with that same gun. Besides, if you can afford to routinely pay for elk hunts then surely you can afford at least 2 rifles. Savage makes some bolt actions that function and shoot very well for not a lot of money. A .223 or 22-250 combined with a 30-06 or 7mm mag would cover you for practically anything in North America.