This could be a timing problem, you don't want just anybody to work on a revolver with a timing problem, send it back to the factory! Before you send it off make sure it is spotlessly clean, be sure to clean under the extractor star on the cylinder, and don't send any nice grips in, only standard grips, if you send custom grips in you probably won't get them back.
To get lead out the best method is one I learned from Bill Wilson of Wilson Combat....Go to WalMart and get a COPPER Chore Boy, these are in the section where they sell dishwashing detergent and dish cleaning pads, only get the COPPER one, do not get the stainless! When you have the copper Chore Boy take an old pair of scissors and cut a patch out of it, don't worry, it cuts pretty easily, then wrap that patch around a bronze bristle brush, and proceed to run that through the barrel and cylinder, you should see flakes of lead coming out, this method works like a champ for getting the lead out!
Hoppe's #9 has no effect on lead, it works on copper but not lead, the other alternative to the Chore Boy method is to get a Lewis Lead Remover from Brownell's, I used to use the Lewis Lead Remover before I learned of the Chore Boy method, the Chore Boy method is far cheaper and works far better than the Lewis Lead Remover.