What would be interesting to know is, how many rounds do they use to proof it with?
Over here in the early days, most gun makers proofed guns their own way. L.C. Smith used twice the powder to proof theirs, and in the mid 20's I believe started to put the proof marks on the barrels. I'm sure most other American gun manufacturers did the same. But again, how many rounds did they use to proof?
I agree to what Bill said, who knows what was done to the gun since it left England, how many times was it re-blued/browned and how much was removed from in/out of barrels.
Like stated a wall thickness gage would make me feel better.
