I will say that the 300 win mag has been the easiest rifle to load for I have owned.
My load with 210 Bergers was 2995 fps.
My load with 215 Bergers is 3035 and I have seen 3050 fps.
My sons 300 win mag shot the 210's at 2916 fps and had more room for speed but this was the accuracy node.
His 300 win now sends the 230 Bergers at 2775 fps.
All these velocities are at 4000' ASL and from an Oehler 35 , so no internet hype here.
All above loads were easy to work up and all will shoot 1/2 moa at 1000 yards.
The 300 WSM
's I have worked with I could not get as much velocity. They shot well but accuracy loads were slower than the 300 win.
I like the brass offered for the 300 win better too.
This is why we shoot the 300 win over the 300 WSM.