RE: 30/06 vs 300 Win Mag
I would go with the 30-06. More than adequate for elk farther than most people shoot (more than 1500 ft lbs at 500 yards with a 180gr bullet), and can easily be loaded down for deer or even varmints if that is what you want. You wont really gain all that much going from 30-06 to a 300 Win. Basically you gain around 250fps, a little flatter trajectory (about 4" @ 400yds, and 8" @ 500), and some more recoil if both are shooting 180gr bullets.