I shot a ladder with retumbo this afternoon. Nosler brass, fed 215, 162 amax loaded .020" off.
I started at 77.6 and went up to 80 in increments of .3 grains. I had a node between 77.9 and 78.5 with the 3 going into a .5". I hit a node at the upper with 79.7 and and 80. Those two were touching. Hogdon lists 80.2 grains as max with a 160gr bullet and my primers were just starting to flatten at 80. Since we had some wind today I shot these at 200 yds.
When I shot my H-1000 ladder I went from 75.7 up to 78 in .3 gr increments as well. It showed less overall vertical but I didn't get any real defined clusters. I had two rounds that grouped about .5 inch between 76.9 and 77.2 gr. I wanted to post some velocities for you but my chrono was being tempermental today.
If you want to try these powders this info is just a starting point for you. stw chambers vary and so do the pressures. Start low as my top end numbers were nearing maximum.
my chamber is min spec match with a .318 neck