Honestly, I'm not sure of the jargon "roller knurling" for truing an action. I have seen a "few" savage action faces and only the PTA's have a relatively clean face. Most look more like they were peened to me. An answer from Fred is would clarify all questions, but those marks look like they were for some type of alignment process to me.

Another thing to note is that the factory recoil lug takes from .012" to .020" to clean up if you consider the stock taken off both sides for at least 90% cleanup I believe Savage uses the high torque value on the threads to compensate for the lack of sufficient contact on the mating surfaces. this can cause distortion, I'm sure the tolerances are calculated and also the reason for a floating bulkhead IMHO.