I continue to use Winchesters and Speers +P load data for W231 with relatively soft 158gr lead bullets of 4.5grs to 4.7grs max +P. Usually I use 4.5grs. These loads run between 830 to 900 fps from my 4" revolvers depending upon the gun and primer used. Lead loads listed by Hodgdon are all downloded to cowboy action levels which is a very mild target level.

For the .357 mag I load hard cast bullets at full power (1,250 fps +/-) mostly using 2400 and AA#9. If I was going to use W231 in the .357 mag with 158gr lead bullets I'd keep the load below Speers 5.4gr max and and less than 1,000 fps with soflt swagged or cast bullets. For hard cast work up to no more than 6.7grs max Winchesters data,