Re: 300WM vs 300 WSM??
I have Sako Grey Wolf 300WSM and a Remington 700 in 300WM. I prefer the 300WSM, I think it has less recoil, and for hunting anything in North America, there's nothing a 300WM can do that a 300WSM won't.
I wouldn't take a shot on anything beyond 500 yards with either gun (that's just me), and both are well within dropping anything at that range (in NA).
The only other disadvantages that a 300WM would have is possibly barrel life, but I'm not for sure on this.
The major advantage of 300WM is more readily available ammo supply.