Barrel wall thickness - Page 9

Craig Budgeon · 07-06-2023, 10:14 PM

Drew my understanding of Britsh proof is that a 12 ga. exceeding nominal size (.729) by more than 010" has to be reproofed before the gun can be sold in England and is marked 12/1 on the barrel flats after successful reproof. Based on that understanding Gibbs would sell a gun with a bore of .735 and is still in proof by .004. Ed Good there would be many Parkers left in dealers gun racks if .030 minimum was the accepted number.

Drew Hause · 07-07-2023, 08:38 AM

That is correct Craig pre-1954.
1954-1989 the bore would be marked in inches, but I have seen some also marked with the 12/1.

Craig Budgeon · 07-07-2023, 10:32 AM

Drew, 12/1 can mean reproof, the gun was originally built with barrels which exceeded .739 dia., or that the gun had been rebarreled which is common in England.

Drew Hause · 07-07-2023, 11:10 AM

Correct, 12/1 = .740" - .750"; if rebarreled prior to 1954
The flats would carry the Crown over R if re-proved.

Interesting collection of proof marks. Originally proved 35-36 by 'P' on the upside-down date code, with '12' and '13/1' (.719" - .728") bore
Then reproved 1959 and marked .729"

J. Blanch & Sons original London Proof 1887-1896 with bore 12 (.729-.739").
The time bomb damascus

barrels Birmingham re-proved (tiny Crowned R) 1999 (BD) with bore 18.7 mm = .736" which could have been the original bore