Oddly enough I've wound up settling on the same load of HP-38 (comes out of the same spout as 231 remember) for my 358-158-RF as I use with the 358-140-SWC.

4.3gr. Gives 859fps with the 140s and 786fps with the 158s.

I was really hoping for 800 with the 158s but probably won't get there without going into +P pressures and I don't want to do that. They actually weigh closer to 161 on average.

Either way my old M&P seems to like that loading the best with either boolit.

I might later on have a look at something slower like Unique, No. 5 or Power Pistol to get into the 800fps range. But for now I need to cast and build a bunch. I find I tend to run through .38 faster than anything else.