I own a .270 that I use for Mule Deer, and a .300 Win Mag for Elk and bigger game. If I were to choose one caliber for everything, I would choose the .30-06. I love my .270, and my .300, BUT the '06 will do almost everything my two gun battery will in almost any situation. The only exception is LONG range where the .270 shoots flatter, and the .300 is flatter and hits harder. The only reason I chose two different calibers is because I live in Wyoming, and sometimes shots can be pretty long. If 99% of your shots are 300 yrds. or less, the '06 is hands down the best choice.