I'm not sure S&W will work on a revolver of that vintage any more. I had a 4" S&W 31-1 that my daughter liked.I say "had" because she now considered it her revolver. This revolver has no finish left and I tried to do a cold blue job, with mediocre results. My plan is to strip the bluing off and Parkerize it.
While I would not recommend it for your particular revolver she keep Winchester 32 ACP Silver Tips in it for house use. Our normal load is 2.5gns of BE under a Lee 90gn TL SWC bullet lubed with liquid alox. I'd have to check my records to see what the OAL is because off hand I do not remember. OAL, or more correctly headspace above powder charge, gets very important in these small cases. It chronographs a little under 850 fps.