Bought one of the John Ross 5" 500 mags and was disgusted by the state it came to me in...sticky crap all over it, that was nearly impossible to get off, some of it left permanent marks on the frame, the nut the grip screw screws in to was completely stripped and the screw itself looked like it had been ran through a garbage disposal. After addressing those issues I took it out to fire it. No joy. 4 out of the 5 cartridges I loaded didn't fire.
What I did;
Replaced hammer spring...a little better, 2 out of five on average.
Replaced strain screw...didn't make a noticeable difference
Upon examining it found the hammer was scraping against the frame as it fell. shims would not have fixed it, as it was hitting against the top and left side, so I polished metal off the hammer until it wasn't hitting the frame anymore. It took a LOT. It was an improvement, but still only 3 or 4 out of five would fire.
I didn't do anything with it for a couple years being rather frustrated with it.
I Revisited it recently and decided to disassemble it and see what I could find.
I removed the firing pin. it had a shiny ring around the back end of it. Looked like kind of a tight fit. So I polished it down a bit.
The firing pin return spring also seemed kind of stiff so I clipped it shorter. After removing that spring I looked in the firing pin hole/bushing. I couldn't see through it. I pushed a pin through it and something moved so I made a small hook out of a sewing pin and pulled out a metal shaving. Not a small one either. large enough to. make me say "wow, that was in there?"
I also noticed part of the hammer was hitting the internal lock components, enough to have scraped it up pretty bad. I polished that up and removed the internal lock components instead of taking even more metal off the hammer.
I put it back together and like magic it's 100% reliable and now I can use it for its intended purpose finally.(woods side arm)
Point of all that is I was astounded how awful this revolver was from the factory, their high end custom shop no less. Combining that with the lousy 29-5 i had with even worse uncorrectable issues without a serious overhaul, and the 360 chiefs special 357 I have that while reliable, has the grittiest trigger I have ever felt on a revolver... I will never buy a new Smith and Wesson again.