Ive worked on a few Remington 742s in the past. Eventually the receiver wears and gets burred and the bolt hangs up. Also no one cleans the chambet and this causes jamming. For an in depth explanation, Google Leeroy Wisners ramblings regarding the Rem 742. For most owners who hunt once a yesr and shoot s box or two of ammo, the gun should last a long time. Here in Hawaii with a subsistence lifestyle, many owners go hunting every week or more. I have seen many burred receivers. I used to remove what burrs i could and tell the owner to keep the chamber clean. Brownells sells a chamber brush. Remington used to have a dog leg chamber brush with a loop on one end for a patch. Im too old for gunsmithing now amd retired. Good luck on restoring your dads gun. Mel
