My powder choices in 300 WSM:
150's 68 gr's W760
165's 65 gr's H4350
180's 65 gr's RL17
Have tried (other than listed): H4831, Imr 4831, Imr7828, Imr 4350, RL 22, H414, RL 25, Imr 4320 & Imr 4064. The worst group of any of these many bullet/powder combinations was 1.5".