I use the Missouri 145 gr. bullets with Unique powder. Also tried some bullets from Oregon, don't remember the company, or load data, but just tried them out a couple days ago, and at ten yards shot 4 inches low. Have to figure that one out.
9245, I would use smokeless powder, as black powder is a mess to clean up, but I would not assemble any hot loads. Starting loads only, as the manuals suggest.
My more or less standard .38 S&W load uses a 125 grain .358 lead bullet, truncated cone, and 3.0 grains of Bullseye or similar. Safe to shoot in top breaks. It shoots fairly close to POA.Like Raljr1 I seem to buck the trend by loading lighter bullets in 38 S&W. Years ago I found a homemade bullet mold that throws a 126gn SWC at .360 diameter. I think someone was trying to make a bullet for 9x19 and made it too large. 3 gns of Bullseye shoots to POA in my Webley. Yeah, the Webley is technically a top break and this is a solid frame load, but not all top breaks are made the same.