I use the max Alliant-listed Power Pistol .357 loading (8.0 grains - this is what they list for jacketed bullets, but cast bullets give lower pressures with jacketed loads) and a CCI magnum small primer under a 158-grain .357 LSWC from Tennessee Valley Bullets with a solid roll crimp. It's a decently accurate, moderate and clean .357 loading, and real pleasant out of my 3" K-frame: sort of giving .38/44 performance, a good easy-shooting .357 loading.

Out of the 3" 65-5, 36°F @ 5950'>sea level:
M 1147 fps/ES 28.46/SD 11.61.

Out of a 4" GP-100, 80°F, same range:
M 1226/ES 9.71/SD 4.35 fps

It's sort of one of those loadings that I try to always keep around. Just a good basic load.