For just about any welding done on a firearm your best bet will always be TIG. Primarily because the heat is so concentrated in a small area.
JMO
Can you tell me if that'd work to weld shut the goofy hole in the receiver used to accommodate the hammer-blocking safety on the Marlin lever-action rifles? A few years ago I asked various gunsmiths if they'd do that and, surprise, no one would touch it! I've always been nervous about doing that anyway for fear of screwing up the heat-treating in the area of the locking lugs. Just wondering.
