I had that problem with two of the same model, although it can affect any S&W DA made in recent times.
I called the factory, and a workman explained that in the rush of production, they sometimes failed to remove enough steel from the face of the extractor rod. There may be a high spot that drags on the lock under the barrel. He explained that if I set the gun down on a table and turned the cylinder by hand, applying a file to it, the high spot would be filed off. He said to go slowly, checking often. Stop when the gun gets to where the cylinder opens normally. KEEP THE FILE FLAT TO THE END OF THE EXTRACTOR ROD and work carefully.
I don't have many home tools, so I just used the metal file on a Swiss Army knife. It took longer than if I'd had a proper mill bastard file, but worked.
Keep in mind that not much metal needs to be removed, usually. Don't think of some way to do this with a power tool. Use hand power.
He said that this is what they'd do if I returned the gun to the factory, so I might as well do it, myself.
Now, this is what fixed MY guns. You should probably get a gunsmith to agree that the same situation is your issue, before undertaking this work. Based on your description, it seems the same thing.
T-Star
