When I got my 300 H&H, I worked with H4831sc and Hunter powders.
Bullets tested were 200gr Partition, 180gr TTSX, GMX, and 165gr GMX.

I sent lots of bullets downrange and burned a bunch a powder testing loads and getting ready for Africa back in 2015-2016.

The load I settled on was:
180grTTSX
64.5gr Hunter with WLRM primer
2906fps

I could not get the partitions to shoot. The 180gr TTSX's bested the GMXs by a little bit. The 165gr GMX's shot fantastic, I just wanted a little more bullet weight..


Arcus Venator