Thanks Bob. You mentioned some of the older barrels appearing to be the same "contour" in some mag chamberings, but is it possible, that they had heavy enough contours back them to handle standard and mag chamberings ? I guess what I was referring to was the rifles of today, such as the one I mentioned, the Remington Mountain Rifle, which also came with a standard contour and a mag contour which was kind of my point. Maybe gunsmiths will shave a few thousands here or there, but I believe, in general the factories have different contours for standard and mag chamberings. I could be wrong though.