Between the top four or so 300 Mags, there is not enough difference to make any difference. My pick beyond doubt is the 300 WINCHESTER Mag. The ammo and rifles and brass and everything is much cheaper and easy to find. No Animal could tell the difference between the 300 Win and 300 Weatherby. By Nosler manual only show about 50-70 fps between the two. The Ultra and weatherby 300-378 will gain you another 100-150 fps. again no practicle difference. Anything a guy can't kill with the 300 Win Mag could not kill it with the others either. IMO. A true step up from the 300 Win Mag would be the 375 H&H or 378 Weatherby.