Back in 1995, while attending the annual S&WCA show in Springfield, we had the opportunity to visit the factory. They showed our group the EDM barrel rifling machine they were experimenting with and also shared some interesting rumor/info.
Apparently the process was so precise, and repeatable from barrel to barrel (read: exactly the same), that the BATF visited them and promptly registered some sort of request/reservation that the process would make it very hard to get unique "barrel signatures" on bullets, potentially causing some interesting challenges for law enforcement. The person giving us the tour suggested that they were thinking about ways to introduce "flaws" in the process so as to keep this from being a problem.
This is, from my recollection, what was indicated to us. The machine was new to them and I'm not sure it had gone into full scale production as of yet.
Just an interesting piece of info, maybe bogus, but the newer technologies (i.e., CNC) were being implemented by the factory to streamline and enhance production techniques pretty agressively back them.

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.............SmithNut