Damascus,
Agree or not it's the best adhesive for the job currently available. I have never used it for a permanent repair or sold a gun with a shim. But there has been an ongoing discussion on expedient and low cost repairs. If the owner wishes to secure the shim with minimal tools or risk of heat it's the best solution. My sole point. Not advancing or promoting the method, simply an answer to the best way to bond a shim in place without silver or soft solder, a method that doesn't require the tools or skill.
