After the original proof, both bores have been enlarged by around.010". This would have been prior to the reproof, so if they still measure the .719 & .729 respectfully they would still be in proof.
The British 3-ton proof is equivalent to about a 9,000 PSI as measured by Piezo Electric crystals, not LUP. US shells are loaded to SAAMI Specs which can go up to 10,500 PSI in 12 gauge, thus the warning about off the shelf US shells. Nice looking gun & appears in reasonable condition. Treat it nice & it will give you many years of enjoyment. Certainly that $450.00 is not even in the Ball Park.
I would have to dig out my proof books to be positive, but pretty certain the original proof was under the 1904 act, just not sure of the ending date on it.
