6.0 grains of unique, 5.0 grains of titegroup, 4.8 grains of 231, all behind a 158 LSWC are my favorite down loaded .357 target loads. I have gone as low as 4.0 grains of titegroup, and 231 but I get better accuracy with the slightly higher velocity loads.
A brisker midrange load? 7.7 grains of unique behind a 158 Semijacketed Hollow point, is an excellent defensive snubby load in .357 magnum.
I have loaded and fired several thousand of these down loaded .357 rounds with no problem at all.
CAS loads are availible from many powder manufacturers for the .357 mag cartridge and are quite safe.
Remember CHECK A LOADING MANUAL dont just use my loads.