What I didn't mention was that I have a few other powders I plan to try, among them being IMR4064 (which is what I'm using now behind the 120 grain bullet) and Varget. I don't have Quickload, and my assumption is that the short barrel will do best with a fairly quick burning powder. Accuracy is my first priority, but if I do wind up using the 120 grain bullet, I would like all the velocity I can safely get - along with the accuracy, if those two will go together.
And thanks, Homesick. I just saw your note. I'll call Nosler.