Original bore?

[Mike Poindexter]

Austin Hogan published data on this a long time ago. As with most of his research (choke shapes, french polish, etc.) it was so informative that I copied it to my Parker files so that it survived to my posterity. I am attaching it. Bottom line is prior to s/n 70,000, 12 ga bores were commonly in the .755 range, while afterward they tended to conform to the .730 range. Enjoy

[Researcher]

In the 1886 Chamberlin Cartridge Co. ammunition catalog they offered special cartridges for Parker Bros. guns with over-size wads.