If the ribs are loose, the temp exceeded 360f to melt the lead/tin solder or the rust failed the joint. If the breach is still solid the temp did not exceed silver solder melt temp. Without looking at them I think you assume more than 360 and less than 1200f if the breach is solid. I see no reason to believe the temp weakened the steel.
For those concerned about heat affected barrels, consider the heat used to make the barrel assembly originally. A torch was likely used to turn the barrels red to silver braze them at the chambers. Even a new modern double today gets this heating to assemble them.
Last edited by Chuck H; 10/08/12 04:44 AM.
