Can I recommend that you take your go gauge, put two pieces of cellophane tape on the back of the gauge where it contacts the bolt face, and see if the bolt will close without a lot of force on the bolt handle? If that does not yield acceptable results I will be glad to let you borrow my .308 Winchester gauges (mine are Manson) and see what you get. If the bolt closes on the Manson no-go you might want to have your gunsmith take a second look at his measurements. Lots of "stuff" happens when you torque up a barrel to an action, but usually in the other direction.
I would like to add that I am not suggesting that the PTG gauges or reamer were not correct. PTG makes some really fine stuff, I know, I own some of their tools. But we should never underestimate the human factor.
