I load cast .45 ACP with whatever I am currently using for 12 gauge. That has been 700X for a long time, but has included 452AA (I am right now working out of a keg of 1981 vintage 452AA bought from a trapshooter's estate.) Red Dot, Green Dot and PB. Next will be Clays, I owe Hodgdon some business because of their help finding pistol data for that 452AA and Clays has been a clean powder in the only application where that matters much to me, light revolver loads.
The only pure pistol powders I have worked with are 231, AA2 and N320. They do well, too.
With loads adjusted to chronograph desired actual velocity from my gun it is really hard to tell a difference. You might could fine tune a precision target load by switching powders, but you wouldn't likely be shooting cast RN for that, would you?
If you have NO suitable powder in the house, I would get some ball powder like 231, AA2 or Titegroup, just for ease in setting and holding powder measure adjustment.