I, like many SASS shooters shoot a Uberti 1873 in 38/.357 and use .38 spl brass with 158 RNFP that I cast with many different powders....most common for me, is using 4 gr. of Unique. very mild and accurate...same with Win. 231/HP-38, Red Dot etc.
My '73 doesn't care about .357 or .38...