Well this is got interesting, from which cartridge for Elk and Deer out to 450 yards or so 30-06 vs the 300 Winchester to some thing about horses or the back side of one. Well 450 yards is getting a bit on the long side, either would do if you can see it and you can dope out drop and more important doping out the wind. There is always going to be trade offs, shootablity vs light enough to carry all day for days on end, after all its hunting not target shooting. That being said, shoot what you what to shoot and leave it at that. As for horses I don't know anything about horses other than I did a little riding when I was a child. So I will not say anything about horses. You could split the difference and go with either a 7mm Remington or 7mm Weatherby and the game would not know the difference and you could build a very nice shootable and carryable rifle to boot.
