I made an educated guesse at a mv of 26-2700 fps. I then ran the numbers at a 4500' altitude. The program put energy at 950 and velocity at 1400 fps at the 1500 yard mark. Still plenty to get the job done.
I was looking at this combo in january. I opted to go with the 7mm Dakota. This pushed mv up 2-300 fps. This gives on game performance out to 2k! The Dakota is basically the same case as the wsm, only 1/4" longer.
I believe my gunsmith recommended a 1 in 8.5 " twist. Might need an 8 twist for the slower mv.