Win brass, Fed 215 primer,75 gr. RL22 & 180 Gr. Nos. BT for Deer & shooting or Accubond for bigger than Deer. This is a classic, proven load that is accurate in most 300WM's it is tried in. I don't like to give powder charges, but is 1/2 gr. under Nos. manual (new manual shows their brass). Please work up slow.
Vel. is usually 3,050-3,100 with a 24-26" tube.
I use RL25 & obtain 3,140fps with a 26" Sendero with great accuracy. Again, work up slow.
The 300WM if a good rifle/barrel is usually easy to work with to obtain good accuracy when compared to other magnums.