I am new to this board and I really enjoy reading/learning from all the people here. I am in the planning stages of building an elk rifle. I have a Rem 700 action and I've settled on 30 cal. My question is; is there much "real/useable" difference out to the 600 yard area between the 300WinMag/300Weatherby/300Ultra/30-378? Some of the info I have seen shows the traj. difference between the 300win and the 30-378 with a 180gr bullet is just over 2 inches at 600 yards. That doesn't seem like much to me. I would really like some real world experience from the people doing who are out there. Thanks for your input.