About three years back I was at the range and had the chance to examine an M14 rifle that had been brought by another shooter.
He admitted that it was a reweld, but said that a great deal of care had been taken in what amounted to remanufacturing. In this process, as I recall, he said that the chopped receiver halves had the edges smoothed and dressed. A jig was then used to keep the receiver halves straight during welding. The welded areas had been remilled and whole receiver heat treated and refinished in dark gray phosphate. There was no trace of a weld that I could find, inside or out. It was a very impressive job and obviously shot very well indeed, as he won his match with it. That rifle was the envy all of us M1A shooters!
I heard last year sometime that the gun had been confiscated, and that the owner had been left with a parts kit sans receiver!
With care, can a receiver actually be rewelded so that its strength approaches that of the original forged, uncut item?
Should we just automatically assume that rewelds are far less desirable than uncut guns?
Is there any way to tell a "good" reweld from a "bad" one, besides the cosmetics of the effort, without specialized testing?