Thanks. I have some Unique left (not enough) and a bunch of W231. I also found some decent looking 158 SWC to try. I may try some of the 158 SWC and some 173 Keith and see which I like better, although the 158 are a lot cheaper since they don't have a GC. Like WCH said, it's the crack of the 357 I hate, not the recoil, and a light 357 should do everything I need around here and get the pistol out of the safe.
You say you have a lot of 231, that's definitely a good way to go toward your goal here. Heavy bullets and fast powder will give you the least muzzle blast. Obviously you have to be careful with a fast burning powder since pressures could rise very quickly but that just takes a little common sense. Even the 158 grain bullets over 231 will reduce the noise level.
Getting back to the pressure, with 231 I'd recommend sticking with the .357 cases to give you a little more room in the combustion chamber. You might have to add a half grain over a .38 case to get to your desired velocity but starting the bullets closer to the throats can only help accuracy.
Looking over my notes it seems I only ever used 5.0 and 5.5 grains of 231 with 158 gr. cast bullets in the .357 Magnum. 5.0 grains gave 990 fps from a 6" barrel so you might want to start at about 4.0. 5.5 grains gave some leading but that was with store bought cast bullets that were likely too hard to properly obdurate.
Not what you asked but hey, this is the internet and no one stays on topic,
, but if you want a nice mid-upper level load of about 1050 fps in that 4 5/8" barrel or over 1100 in a 6" barrel, 7.0 grains of True Blue with a 158 grain cast is a real load that works and isn't too "cracky". That 7.0 grain load has been consistently accurate to really, really accurate in every single .357 revolver I've tried it in. Lower it to 5.0 or 5.5 grains in .38 Special revolvers where it still consistently provides top level accuracy around 850-900 fps depending on barrel length.
