Sling Shot, this is normally done to correct a headspace problem. Or if your rifle, new that it may be, was not set to minimum headspace the accuracy will probably be less than it could be. Setting the barrel back one complete thread or turn, .0625" in the 700, keeps the markings and sights alined. The chamber is then reamed to the correct depth. This will improve the accuracy all things being equal but I would consider it part of blueprinting the action. For instance if the face of the receiver and the face of the barrel shoulder aren't square then it probably won't help much. Anytime I set a barrel back to correct a headspace problem I also true the reciever, bolt lugs and bolt face as a part of the job. George