Thank you Edgar. It appears the pin is measuring the forcing cone wall thickness? Could you please post the end of the chamber measurements?
It has been my experience that the thickness at the forcing cone frequently exceeds that of the end of the chamber. The angle of the forcing cone is more acute than the external taper of the barrel; as illustrated
This may not apply to small gauge and continental game guns, and does NOT apply to guns with chambers lengthened.
And so we all don't have to go looking. End of the chamber measurements.
http://parkerguns.org/forums/showthr...096#post158096
http://parkerguns.org/forums/showthr...?t=1565&page=4
English:
James Purdey (1898) 12b., 2.5" chambers: ≥ 0.100.
James Woodward (1909) 12b., 2.5" chambers: ≥ 0.098
James Woodward (1909) 12b., 2.5" chambers: ≥ 0.103
Boss (1897-8) 12b., 2.5" chambers: ≥ 0.090
Westley Richards 12b., 2.5" chambers: ≥ 0.090
James MacNaughton (1895) 12b., 2.5" chambers: ≥ 0.095
Wm. Pape (1898) 12b., 2.75" chambers: ≥ 0.100
EM Reilly (1887-1904) 12b., 2.5" chambers: ≥ 0.091
Henri Egg (1870) 12b., 2.5" chambers: ≥ 0.108
WH Monks (1875-87) 12b., 2.5" chambers: ≥ 0.116
WC Scott (1905-6) 16b., 2.75" chambers: ≥ 0.105
Francotte (1938) 12b., 2 5/8" chambers: ≥ 0.098
Westley Richards (1905) 20b., 2.5" chambers: ≥ 0.098
WW Greener (1922) 20b., 2.75" chambers: ≥ 0.098
Belgian:
Francotte (1894-5) 12b., 2.5" chambers: ≥ 0.085
Francotte (1896) 12b., 2.5" chambers: ≥ 0.085
Francotte (1930) 20b., 2.5" chambers: ≥ 0.095
French:
Verney Carron (1950s) 12b., 2 5/8" chambers: ≥ 0.100
German:
Wilhelm Brenneke (1902) 12b., 2.5" chambers: ≥ 0.110