What extreme spread (ES) and standard deviation (SD) do you find adequate in your 38 Spl / 357 Magnum loads? I usually test factory ammo for their ES/SD and attempt to better these with my handloads…which in 38 Spl +P isn’t too hard to do. I usually aim for ES below 50 and SD below 15…I also find that the higher I run my loads the tighter my ES/SD become…powders which I obtained lowest spreads in 38 Spl +P using 158 gr cast are Power Pistol, BE-86 (best accuracy) and W231. In 357 Mag with 158 gr and 170 gr +/- Keith’s in upper mid range velocities, N340 has given me the tightest spreads and best overall accuracy.
Please tell me your experiences.