at the 416 GNR load data and the 476 GNR load data. They, along with the 450 GNR, use the same basic brass and the bullet weights are basically the same, so there might be something in there that you can use.
A lot of gun writers give us 25 different powders and a ton of loads and all this does is confuse me. We may only post 3 or 4 powders in my reloading manual but they all work and work very well. My recommendation is not to waste time playing with a powder not listed and simply go buy a can of H-322, 3031 or 4198. The H-322 was by far the best and most accurate in several Encore barrels we used.