I have concluded that the hammer needs to be replaced. Because, having it reworked and casehardened hasn't been the solution. Does the sear need to be replaced too.? Can they be replaced with Winchester M 92 parts? If it was your choice would you go with Rossi parts or Winchester parts?
I don't know if the orginal smith who did the work screwed it up or not. He has a good reputation. I am personally aware of him doing the triggers on 5 Rossi's, 6 Marlins, 2 Winchesters, a Remington, 2 Henry's, and 3 TC Contenders. All are shot regularly at our silhouette matches (Hunter's Pistol & Lever Action). I do believe it was defective from the factory as my brother's rifle, a consecutive serial # to mine, was better to start with. They were about the same after being done by the same smith. His has stayed the same. I have another Rossi, a carbine. I wasn't complaining about Rossi firearms. But given a choice between an orginal Winchester in good shape and a Rossi configured the same who wouldn't choose the Winchester?
Dewight