I just purchased M-70 Stainless in 7mm WSM
. I am curious if you got any velocity with H4831? I am also impressed that you have tried so many powders.
I am interested in 160 Accubonds which are the longest bullets that could fit in the magazine. My guess is that R-25, VV N-165, H-1000, Ramshot Magnum, Magpro would be the velocity winners with 160 gr bullets. I spoke with the late Bruce Hodgdon about H-1000. He had the powder made for 160 gr bullets in the 7mm Remington Mag.
What powders from my list can you eliminate and what is the criteria that you used?