I'm going to assume this is for light, cheap, target shooting loads for a .357 gun, for which I'll suggest 158gr SWC, either cold swaged, or cast for the easiest to get load data. Use mid 38 as starting loads, or even .357 starting loads for lead are pretty mild.
Actually just checked Hogdon's website and starting load for 158grSWC in .357 IS a .38 spl load -
3.4 HP-38
796fps
12,600 CUP