Surely 'proof' is a relative thing with these old guns.
At that time nitro proof was voluntary anyway.
That gun may be .744 in one barrel, but it may have left the factory at .728" as 13/1. The absolute essential number is the WALL thickness.
This thing about proof started on this BBS back in the late 90's and it always fails to make me see what relevance it has in the USA, as long as the wall thickness is suffienct to be considered safe. For example: the barrel with .737" bore measurement is hardly a concern, assuming it left the factory with .032 -.037 narrowest wall thickness, and it was just under .729, say ..727", there is still easily enough wall there..its all relative...its all about the wall thickness, not the bore diameter.
