HL & CL,
Years ago I welded a stainless case knife handle on a custom 03 Springfield bolt. Wrapped the body in a wet rag for a heat sink, used a high nickel rod for the weld & air cooled after. It never changed the bolt color a 1/16th from the bead, the rag was still wet around the joint. smoothed the bead with a Dremel grind & polish. Looks fantastic. Plus I don't have to worry about pulling the temper from the bolt. You can barely see the joint. The stick weld process is fast & the nickel rod gives a hi ductilty to the joint so there is little chance of failure. It also helps to know a welding instructor to make the weld in minimal time.