How does the other bolt gauge in the rifle? What is the condition of the rifle and does the bolt appear to date with it? Do you have any other older 30-06 rifles with which to compare fired cases with? I have never gauged any of my rifles. All I ever do is give them a thorough cleaning and examination. If everything looked good, then the rifle got a few test rounds put through it (tied to a tire or bench and fired by rope), and the cases examined. If everything still looked good than I shoot away.