Factory 150gr ttsx ammo chronographed on avg 3354fps for the 300 win mag and 3343fps for the 300 wsm. The box says 3285fps for the 300 win mag and 3310fps for the 300 wsm. 165gr fusion chronographed 3175fps in the 300 wsm and 180 non typical chronographed 3085 in the win mag. With being able to load longer in the 300 wsm and being restricted to swami in the 300 win mag, they are effectively the same performance for me.
