Posted by David Williamson on January 26, 2016, 8:02 pm, in reply to "Old Guns"
Dk, in your measurement 18" from muzzle you gave a reading of .11 wall. Did you leave out an 0 before the 1, .11 is hundred ten thousands (.110) Not being picky but that is quite a difference.
I am always leery of old guns described as having "mirror bores". Can almost be assured that they were honed, but some of the older shotguns (pre-1890) did not have what became the standard .732 bore of many makers later. I have measured a few 12 gauges that were .740 and even .750. On early Parker 10 gauges it is common to see bores .800.