My thoughts are like this: There may be no difference in teh action length between your 30-06 and the 308, early years they only made one length. Early on the barrel breach was recessed like a Remington is today, then they went to a flat breach, it is easy to tell which you have by looking. The bolt head fits into the recess on the ones with recessed breaches, so the locking lugs are back from the bolt face about a quarter inch or so. Not really too big of a problem, but it does take a little work on the barrel to make it fit the older guns. The barrel nut and threads are the same on old or new unless it a newer target action or one of the Magnums, then the barrel threads are larger, but this is not very common and will not apply to your gun, only to new barrels or barrels taken off newer guns. Good luck, Larry