If you really want the best advice regarding specifics for powders Dougs Message Board is the place. There are guys there that have several savage ML's each, including .45 and .40 cal conversions and are nuts about knowing everything, so have all your answers. I love my sav, but invest little time in it, as I am satisfied with what I have gotten. By the way RW is on Dougs Message Board from time to time. 4759 is a popular powder as it is a reliable powder that is not temp sensitive, yet give you good fps performance. If you are looking for higher performance then you could go to 4198 or a duplex load.