Hey, that's a great chart, RB.
Good news for all you Crocket .32 shooters, you're actually shooting a 150 bore gun. That sounds mighty impressive!!!
IIFC, in the Dixie Gun Works catalog, in the reference section at the back, they also list bore sizes and after they go 3 bore, 2 bore, 1 bore, it goes into an alphabetical mode, like A Bore, B Bore, C Bore, etc. up to over 2 inches.