Traditional Colt DA's
The traditional Colt revolvers, especially the Diamondback and Python, have a reputation for being about the smoothest action around but one of the hardest to work on and get the timing back right if it needs it. The rebound lever does so many things inside it isn't easy to get everything back in time if you have to replace one. It isn't just a "drop in" part. Often other parts have to be replaced along with it to get it right again. If someone not familiar with the system has worked on one sometimes you have to figure out what was wrong in the first place, then what they did to it which may have compounded the problem. The local police tell me they can't carry one on a motorcycle. In a holster, saddlebag, or faring, they have been known to fall apart. I never experimented with that, but I do have to carry an ambassador fishing reel in a plastic bag on my Gold Wing so I'll have all the parts to put it back together again. Sounds ridiculous, but I think they may have a point.