I have 5 S&W revolvers, 3 of which had to be returned to the Mothership a total of 5 times. The 3 which were returned all grouped well, but shot too far left despite adjusting the rear sight all the way to the right. During my initial revolver checkout procedure, all of the barrels looked straight, although two were Scadium-framed with barrel inserts. Two of the 3 were Performance Center models (386XL and 325 Thunder Ranch) and all 3 had internal locks indicating they were manufactured more recently than the 2 which shot straight.
One comment directly comparing all 5 is that, despite the PC revolvers having smoother and lighter triggers than the non-PC models, all of them needed to, and have had, the internals polished which made all of them better.