Thanks for all your replies, I talked with the proofmaster and made my decsion. If I am to own it and feel good about it, it will eventually have to be sent in for re-proof plain and simple.
Big mistake. Far better to assume the chambers were lengthened and don't go having a proofhouse put a stick of dynamite in it. Instead, have the chamber walls at the forcing cones measured by someone who knows what he's doing. You may find plenty of steel, .150" or even more. No one could ever have been shooting heavy loads in this gun anyway, well maybe once or twice but that's about it. You'll be shooting light loads too. I have nothing against proofing new guns but I think it should be approached with caution in used guns and then not done. Most particularly with an expensive piece of art like a Boss.
nial
