Sorry, no data on WST, just never used that powder.
I do have a Model 52, and a Clark 38 Special.
I have tried all sorts of cast bullets and commercial hollow base wadcutters. I couldn't get any cast bullet to shoot worth a darn, and of the hollow base wadcutters, The Remington hollow base wadcutter is the best , hands down.
As mentioned above, 2.7 grains of Bullseye is a good load, as is 3.1 grains of Winchester 231. However,my favorite load is 2.7 grains of 700X. Take a look at the 50 yard target below along with the data.
The Remington Bullets are fat, about .360, and the Clark Chamber is tight. I get best reliability if I give rounds a light roll crimp in the seating station followed by a taper crimp in the last station. In my model 52 I don't have to do the extra taper crimp, but I do it anyway because that's the way that tool head is set up.
Actually, I didn't need to do the taper crimp with the original barrel that was in my Clark, but when I had them replace the barrel a couple years back, I couldn't get it to feed reliably until I added the taper crimp step.