It seems strange to have 1 barrel .729 and the other .719 but I have a theory, based on having owned several Britt boxlock waterfowlers. At the time some of these guns were made shells with felt wads were used and the gunmaker wanted to insure combustion and perhaps increase performance by having tighter constriction in the barrel.
Usually, when I see a difference in bore measurements like that, I think the worst, but, it appears this gun was proofed that way. Nice to find an English gun with 2 3/4” proofs at 3 1/4 tons.
Best,
Ted
