The longest distance I ever shot at an animal was at bull moose at 325m or so with my custom 21" barrel LH Rem mod 788 in 7-57 AI. It's doable to do the same feat with 338Federal as well. The only question is what would you rather have in your hands when creature with the ability to fight back is within stone throw or closer in the bush....7mmMag with typical 150gr NP or 338Fed with typical 210gr NP? Don't ask me the same question, I allready know the answer....
Easy, when you put such limits on distance the .358 Win with the 225gr Partition is best (out of .308 based cases). For real life, the 7mm RM is the best.