Originally Posted by robocop10mm
Humans make mistakes. Sometimes those mistakes have catastrophic results. In my experience, Smith and Wesson quickly and happily fixes their mistakes. The inspector will have some "splanin" to do for sure.
Humans do indeed make mistakes, and that is to be expected. However, a series of errors are usually the cause of something like this example leaving the factory. Not knowing the exact sequence of steps that S&W uses to produce a cylinder, I can only guess, but I would bet that no less three people handled that cylinder, prior to the gun passing final QA inspection.
Think about the things that have to happen to make a cylinder. First, turn the raw stock to the proper diameter and form the boss that the cylinder ratchet will be cut from. Then the ratchet, locking lugs, cylinder flutes and chamber pilots must be cut, all timed correctly so that the chambers will align with the barrel when the hand is cycled by the action. While the location of the flutes is not critical to the timing of the finished product, they do need to be positioned such that they are between chambers, rather than over them. Once the machine work is completed, the cylinder must be fit to the crane and the action of the gun must be timed for proper chamber alignment.
Even though all this machine work is done by CNC equipment, after every stage of machine work, it would be typical for the machine operator to de-burr and check the parts for dimensional accuracy and make any adjustments to the CNC program that may be required to account for such things as tool wear. In a typical high production machine shop, as many steps as possible would be done in a single setup in the machines. To cut all of the features of a cylinder would likely be three setups, one for the lathe work, and two for the mill work. These separate setups would likely be done by different people at various machining stations.
This particular "oops" was not created by a single person's lack of attention. I believe it is the result of a much larger problem within society that I call "The pursuit of mediocrity", the idea of "it's good enough" or "it'll be OK". Taking pride in quality work is a trait that I think is rapidly departing society. Couple this with the practice of replacing highly skilled machinists with "machine operators", and other such reductions of skilled labor and it is a recipe for marginal products of questionable quality.