IMR 4350 was also Whelens favorite with the sierra 180 btsp, in his book "why not load your own" he recommends 56 grains for all around hunting and 57 as a 1000 yard match load but cautions not to use it on hot days as pressure is high. This matches hodgdons website where they list 56.5 grains as a max load with that bullet. I worked up to that load and have been very happy with it. Dropped a spike elk last fall with one shot, my first one shot elk. As an aside, this is one reason I really like the IMR powders, they seem more consistent year in, year out, from manual to manual.