I get terrific results with 4.8 grains of HP38 (W231 is the same powder)...under a 124 jacketed bullet, either FMJ -RN or HP. COL = 1.10", Winchester SP primers and mixed brass. Dead nuts accurate in all three of my 9mm pistols.
This is not a maximum load, but it is hot enough for SD (and I use it for that, with HP bullets). However, I would advise starting at something like 4.3 - 4.5 grains and working up from there.