Savage cuts threads in the profiling operation on a Mori Seiki CNC turning center with a single point tool. The threads are cut in 7 passes. I can't say it's more consistent, because it is not. I've measured thread shanks on hundreds of take off barrels and found that the tolerance is quite wide....wider than than what's on their own prints.

As far as chambering with a boring bar, that has been tryed with no success. It's harder to hold a dimension in a production scale that is required for that specific operation. And by the way...Savage does not chamber their barrels on a lathe.