A good example of that swell Bangor Punta / Lear Siegler Era quality control from Smith & Wesson would be
this Model 581-1, made shortly after the sale to Lear Siegler.
I ran into it when it was owned by Oleg Volk, who had complaints about it shaving lead and not being terribly accurate.
On examination by my gunsmith friend, Shannon Jennings, it turned out that the barrel and the top chamber in the cylinder were not remotely coaxial. The centerline of the bore was a few thousandths higher than that of the top chamber. Either the factory or some previous owner had already had the forcing cone relieved as much as was safely possible, so the gun was essentially a jacketed-bullet-only gun, and don't expect to win any bullseye matches with the thing.
There was no fixing it short of unscrewing the barrel and screwing it on to a whole new frame that wasn't messed up.
The thing is, having the threaded hole in the frame for the barrel shank cut too high is the sort of problem that can only be caused by setting up a fixture incorrectly. That's not the kind of error that only affects one gun; there's probably a whole day's worth of 581 frame production running around out there with that issue. I assume that the forcing cone relief was probably done at S&W and the result was deemed "within acceptable specification".
(Then there was the NIB Colt SF-VI that Marko bought back in '00 where the barrel was threaded in at an angle. Not clocked off on the longitudinal axis, but stuck into the front of the frame at an actual angle...like, if you looked down on the revolver from straight above it, it was clear that the bullet made about a one or two degree right turn upon entering the forcing cone.)