I think where TRShooter is from (he did not Say) (it does not sound like it is near Earth) he may not be able to get any ammo for anything other than the 7mm mag. It does not sound like he has any experience with any other cal. To his defense the 7mag is 10x better than any .338 if you can not get any .338 bullets.
I have to say thanks to this site and its "cheating experts" (what ever that means)as they have just converted annother un educated sap. As I will soon be building a 338 edge.
A special thanks to TRShooer as this post has made me evaluate the balistics of my 300wsm and 7rem mag and have made me see just how superior the .338 edge is for true long range hunting.