Re: .300 WIn Mag
Fed 215 GM or a CCI 250 primer.
75 grans of H-1000 and work up.
We found a sweet spot at 77.
.005" into the lands.
As for dies. I would recommend redding "S" type bushing dies and if the funds are available go with the micrometer neck sizing die, micrometer seating die and the body die to bump the necks back when needed. These dies capture the case in a retractable sleve and hold it square before and sizing starts.