Well, thats great no one was seriously hurt. Did you ever think to send the barrels off to have the walls measured? Maybe the bores were beautiful cause they might have been honed and polished at one time during its life? Very curious. I use almost the same load you use when I shoot my Damascus guns, I almost exclusively use IMR 800x for my loads, they are so mild I cant see them blowing up a cardboard wrapping paper tube.

Again, glad to hear no one was injured.

Dustin