Thanks again for your thoughts. Personally, I would have been uncomfortable going DIY one this one fearing I might ruin a valuable item. In fact, I am prone to leave any gunsmithing beyond minor cosmetics to a professional. In this case, I was pleased to have this experienced pro's thoughts on what heconsidered the exceptional hardness of the reciever after he used a new .30-06 reamer to correct the headspace and carbide tooling to do the gas relief. It was not cheap, but then the rifle came to me free with the trade of another weapon I picked up off the deck of USS Denver in the evacuation of Saigon.