No, take a couple thou or mm(0.1 or 0.2mm) off for the Austrian method of measuring and say that takes you down to 8,6mm. It will be close.

For the period, um most of the Austrian Sporting Weapons mimicked the Military Chamberings plus the era would be right @ the cusp of the transition from Blackpowder, which I would expect this to be, to Semi-Smokeless powders.


Hochachtungsvoll,

Raimey
rse