Green Dot isn't listed as a choice in the Lyman handbook ....
Its listed in Alliants loading manual.....
All thats means is none of the engineers at lyman decided to use green dot in any of their test loads, Thats Because there are plenty of better powders for the 357 magnum. Green dot is probably one of the least popular powders for the 357 magnum, probably because its not exactly the cleanest burning powder.