I owned one for years. The double action pull wasn’t great, but it wasn’t terrible. I used .22 Snap Caps and spent cartridges to dry fire it and over time it seemed to get better. Unless you have 3 hands, are very mechanically inclined and have the patience of a saint I do not recommend complete disassembly.
The first time I attempted to disassemble the gun there was no internet and, as far as I know, even with the internet there was no info on disassembly and reassembly except for the PDF schematic Gun Parts Corp will sell you for $1.50. If I knew what happened to mine I would PM it to you.
Anyway, what I did back then to help maybe loosen things up was I pulled the grips off and removed the cylinder and crane and I flushed the guts with brake cleaner a couple of times. At that time I didn’t have the nerve to fully tear down the gun. Once I flushed it out a couple of times I used Rem Oil and their handy little red plastic nozzle to shoot a little (little) oil in each opening and cleaned everything up and reassembled.
That did help. Try it.
A few years ago I offered the gun to my sister as it was out lr father’s. She wanted it so I tore the whole gun apart and cleaned it up. The internals were in great shape. I made a jig out of wood (plywood with little wooden dowels to match the pin holes in the frame) to set the parts up as if they were in the gun to see how I could reassemble it. It took me a few tries, LOTS of cussing and perseverance but I was successful. I did not try to change the trigger pull or hone the trigger interfaces.
When I got done the trigger pretty much felt the same. I was hoping there was some gunk in there that I may have knocked out and the trigger pull would miraculously get better. It didn’t but I didn’t want to tamper with the parts and give my sister a gun with too light of a pull.
I do recall reading somewhere that any lightening of the DA pull really lightens the SA trigger pull so if you decide to disassemble the gun please be careful. The guy that did the write up that I read said that he ended up having to replace parts he had gone too far with. I doubt Gun Parts Corp has many of those parts anymore.
Oh, and I did replace the 2@ barrel with a 4” barrel hoping that would help with accuracy and help stay on target when using a DA trigger pull. It helped very little.
I wish I could tell you a magic solution but there really isn’t one.