Some old catalog ammo data I have shows both the 32S&W and the 32 S&W Long as loaded to the same velo. Old ammo I have shot really felt the same, too. The Long case should have a bit lower pressure, all else being equal. IIRC, the Colts 32 New Police (Not the same as the Colt 32 Short and Long!)was simiar to the S&W Long, but with a lead flat nose bullet, rather than the full round nose. If these will chamber up without forcing, and the bullet nose does not protrude from the cylinder face they would likely be OK in a sound, SOLID frame revolver. BUT....it isnt recommended to shoot cartridges other than what the gun is marked for; i.e., just because it fits doesnt mean we should pull the trigger, hey.
FWIW, I had a nice, tight, S&W 3rd mdl. dbl. action tip up from about 1889; it predated smokeless powder so it was a true black powder gun. I shot only a few of the old (say, 1930-40ish) ammo I had and it was fine. Even so, in deference to the old steel, the weak design and just plain respect for an old survivor, I decided to only shoot black powder (or BP sub. powder) loads in it. It was very accurate and the smoke was an added bonus.
