you should post your questions in the "guns" forum, you would probally get more replys.

you can't go wrong with the regular 300 win mag (win mag), know lots of people who shoot it. my buddy just got a 300 ultra mag and the ballistics are a bit better than the win mag and he really likes it, bullets are expensive though. don't know much about the winchester short mag (WSM), it's fairly new ...uses the same bullet with a shorter case from what i understand.