Can't speak to 230gr cast, as I only shoot 200gr LSWC's. But with the 200's my favorite powder is Titegroup. I buy it in 8# jugs for about $90. And at an average charge weight of 4.5grains, it give me about 1550 loads per pound. Or, about 3/4 cents per load. Very economical and very accurate.
I use 5.6 grains of 231 and 4.1 grains of N310 with both Rainier and West Coast plated 230 grain RN.
In addition, I use 4.5 grains of N310 with Meister 200 LSWC and 4.6 grains of N310 with West Coast plated 200 SWC and get about the same velocities for each. These two 200 grain loads just make IDPA major.
All of the above I shoot out of a Commander length 1911.
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.
Unique- 4.2 for lite loads, 5.0 for medium loads, 6.0 for hotter loads. All work with 18# recoil spring. 1.245-1.260 OAL. No lead problems, doesn't smoke too bad. Had alot of smoke with Titegroup and Clays. Tracy
Unique has been pretty good while Red Dot made for some real snappy loads. I picked up some Blue Dot for my 10 gauge that I also want to try for the .45 loads.
For my rifle loadings I'm pretty much set on particular powders, but with handguns I pretty much just use what I feel like since for now they are still in plinking/target practice mode. Eventually I'll settle in, but don't have a direct need at this point.
So far I've loaded only 230 MC and 200 lead SWC for 45 ACP. I use 5.0 grains of Bullseye and OAL of 1.250 for both loads. Don't even have to change my press.
230 MC has velocity of 825 fps.
200 SWC has velocity of 895 fps.