I probably shouldn't post since I don't own one...but I'll offer a little support to the previous posters.
My Lyman Manual, 49th edition, suggests Red Dot, 231, Unique, N350, 2400, & IMR-4227 for jacketed 240 gr bullets and adds Titegroup, Bullseye, Universal, N320, SR 4756 for a cast 240 gr bullet.
My Hornady Manual, 11th edition, suggests Bullseye, HS-6 Unique, Universal, Powder Pistol, SR-4756, N-350, Accurate #5, & Blue Dot.
You have probably done all this research already but faster burning powders seem to be the favorites.