Ok, thanks BCB, appreciate your thoughts. The reason I have that wide range of Ba and Loading Ratio is that I wanted to figure out what powders are best for subsonic loads, and to understand why. It seems like TrailBoss is a good choice, but then I was surprised that it wasn't showing up as usable in the powder list. There doesn't seem to be any official user support for QuickLoad, but maybe I'll try contacting the developer directly.
By the way, something I realized when doing this is that a lot of the pistol powders that people usually recommend for subsonic loads need _very_ low filling ratios. Seems like that would give you a really unreliable load where you have to bump the powder into the bottom of the case before each shot. Discovering things like that is why I like QuickLOAD.
Dirk