I will be following this - I have a much "newer" one - made in 1955 - in 30-06. I have not fired it yet, with anything - I was under the impression that the fourth action screw - up under the barrel in the forearm, whether tightened or loosened, might move groups on target. I could be totally mistaken about that.
Also, from my Dad and others - I think those rifles were from an era where a three inch group at 100 yards was thought of as a very accurate hunting rifle. I suspect it was about that era's ability to produce balanced bullets, powders that were available, etc. If my Dad was typical, a hunting rifle such as that was not fired a lot at targets - no shells to "waste" ...