This subject was brought up a few months ago and I questioned that it would not work for fear of the solder hammering out making the barrel loose, but I discussed it with Wayne last time I was at his shop, that's how he does it using soft solder, he said as long as the shim is firmly seated against the pivot, there's not enough solder to hammer out and it will work fine. I forgot all about it
until I decided to fit the 260 Rem barrel to a different frame today! I cut a .012" steel shim that fit the pivot, then annealed it, sanded the back side of it a bit, then degreased it and the pivot. I wanted to be able to hold it in the pivot under pressure and then heat it all up and seat it, so I tested a couple drill bits for size that would hold the shim against the pivot with no gap behind it, found one that was .352" in diameter and clamped in place, there was no gap between it and the pivot.
Next I needed something I could use beside a steel drill bit, didn't want to solder it in the pivot accidentally, so I decided to use aluminum, found an old 3-piece shotgun cleaning rod I had that's .375" diameter, cut a short section, chucked it up in the drill press and turned it down to .352" with a file. Using 60-40 acid core solder I tinned the back side of the shim and the pivot, after they cooled I clamped a large spring clamp($4 at the hardware store) on the short piece of aluminum rod against the shim and on the latch shelf on the other end of the underlug, then heated the entire works with a propane torch and watched it fully seat in the pivot as the solder melted, worked like a charm!!
The all I had to do was cut the pivot to .375" to fit it to the new frame.
Tim