Anything between .223 and .458 Lott will kill a big game animal. Find what you like that will perform at the range you are most likely to be shooting and go with that. You are the only one that needs to be happy with your rifle.

I like to shoot long range, but where I hunt, you can't see over 100 yards, much less shoot that far, so buying a rig that will shoot 1000 yards doesn't make sense to me.