""Will also try 8.5 gr HS-6 with both primers next and retry 9 grains with both primers and lead bullets. I think also increasing the crimp may help with unburnt powder. I may also try to go 8 gr and the 240 gr bullet as I think a heavier bullet pushing back against the HS-6 may give better burn.""


One of my standard loads for range shooting is :
240gr LSWC, 10.5gr HS-6, LPP (not mag). I use a good roll crimp.
Gives me right at 1000fps from a 7.5" Ruger Super Blackhawk Hunter.
Extreme Spread was 44 fps, Standard Deviation was 15 FPS
I can do 1" groups easily at 25 yds, rested.

Very easy shooting, and the pressure is high enough that there is no unburnt powder.