The builder of my old 36 year old 50 cal. (39"bbl.) SMR flintlock used 1/16" (.062) piano wire to pin the stock through 4 underlugs. I was told by our M/L club the piano wire pins seemed to offer just enough "spring" to offset any moisture expansion/contraction in the stock (maple) over time. The underlugs have a single drilled 1/16" hole...I removed the pins to check for under barrel rust of which there was none, and no problems with stock and pins were not rusted. Obviously the piano wire worked. The rifle may have been fired a few hundred times. I re-installed the piano wire pins after minor cleaning. I only question this because I had never known anyone to use piano wire to pin a barrel to stock? Thoughts?