Thanks for all your replies....
Both the 75 and 85 have the mounting screws in the same place. But the stocks are very slightly different.
Well today i managed to try out my first batch of homeloads.
150gr sst RL22 powder col 2.900" Sako 85 .270wsm
i Tried from 64gr to 66.5gr with the 65.5, 66 and 66.5 being noticeably better grouping. I will try these loads seated in by 10 thou and 20 thou more as soon as i can.
I chrono'd the 64.5gr ones at 3140fps. so should be able to hit 3200fps with the higher loads and there was no signs of pressure, well ok only a tiny flattening of the primer.
So far its looking to be a great rifle and calibre! So far even on its lower load its producing more velocity/engery than my 7mag did with the same weight bullet.