My favorite .300 Winchester load is a 165 Sierra, over 78 grains of H4831** with either a Federal 215 or a Winchester magnum primer. These loads put the projectile down the barrel at just south of 3,200 FPS from a 24" barrel. The indicated velocity in the Hodgden manual is 3,180, but the last string of 20 that I put through a chronograph indicated an average of about 3,198 FPS.
Just as an FYI, this is the same load I use with my Sierra 168 Match projectiles. Both are loaded into form-fired brass, and neck-sized only. These loads average between 0.5 to 0.75 MOA, for 3-shot groups at 100 yards, off the bench and sandbagged.
**Indicated as Max-loads.
Doc2005