Don, on old field guns, I would rather have a thin shim in back of the forend lug to bring the lug tight into the hook and have a gun that does not rattle when closed. I realize that this fix does result in a minor off face condition, but the use of compression formed shells makes a thousanth or two of off face a "non-event" as long as the lugs are tight in the slots. Of course, if expense is no object and the gun is of very high quality, a proper shimming or replacement of all offending areas is called for.
