What Montana marine stated about the .308 vs. 300 mag. is something most don't bother to consider. Actually the biggest 300 mag. advantage is that, if you sight them both so that their maximum rise above line of sight is 3" or so, the 300 mag. gives you a lot longer point blank range and a lot less drop at 600 yards. These are less important than they were before rangefinders became available.
However, sometimes you don't have time to use the rangefinder. I prefer not to. When I went elk hunting, I sighted the 300 Weatherby so that, by comparing the width of an elk's body with the distance from crosshair center to where the crosshairs got thicker, and allowing for errors, I thought I could make a 400 yard shot, but not longer. As it happened, I shot a bull at only 50 yards.
