My very first .32 Mag was a S&W Model 631 Super-Kit-Gun. I originally (about 20 years ago) worked out a Unique load that duplicated the factory load (I did not want to go any higher pressure than factory with the little J-frame), but Unique does not meter well making reloading slow. I tried WW540. It worked well and metered great. Then 540 was dropped. I went to HS-6 (which was reportedly a duplicate of 540). It seems like it really is a duplicate. I dropped down and worked up again to exactly what I was using with 540 (5.6gr with an 85gr Hornady XTP or a 98gr RCBS RNFP). It matches the velocity of my factory 85gr jacketed load, but it less than what is published by Federal.
Later on, I bought a Ruger Super-Single-Six. It can take a lot more pressure than the S&W. I worked up to 8.5gr of 2400 with an 85gr XTP (remember this is MORE than factory pressure and needs a solid gun). I later reduced it to 7.5gr to make ejection easier. A very accurate load that is actually higher velocity than factory loads and about equal to published loads. Later on, I came across a Ruger SP-101, dropped down the 7.5gr 2400 load and worked up again for it. It can also take the load. The only problem is that with a 3" barrel, it can double as a flame thrower. It burns the HS-6 much more thoroughly, although a little slower.
I recently bought a S&W Model 331 ti, titanium cylinder, 2" barrel, aluminum frame, DAO. The 5.6gr HS-6 was as accurate as could be expected, but the titanium cylinder got VERY dirty, VERY quick. Within two cylinders full, I had to pry the cases out. I sent it back to S&W to have the chambers repolished and recoated. That helped a little bit. I could get to about 30 rounds without it getting too dirty. Better, but not good enough.
I am now working with WW231 powder. I remembered that it was the cleanest powder I have ever used. However, it was never better than my other powders in any other way, and cleanliness was not all that important with steel cylinders, so I quit using it. Still kept the bottle around, though. Started with 3.6gr of 231 and have since worked up to 4.0gr. It is a great improvement in cleanliness. I could probably shoot up to 50 rounds with 231 before it got too hard to eject. Accuracy is as good as can be expected with a 2" barrel and a DAO action. Next to try is 4.2gr. If it works well, that will probably be my maximum, based on loads I have collected from all over.
Here are a few of the .32 H&R Magnums I am working with.
P.S. The S&W 331 is a great concealed carry gun. Even with the dirt problem, I have been carrying it for a while with two carry strips. There is no problem with 18 rounds tying up the gun since S&W polished it. It is small enough to hide in a pocket easily and is light, light, light. I can also shoot it more accurately than my 642 (same size) in .38 Special. Also, the S&W Model 16-4 shown above has since been rechambered to 32-20 WCF.