doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Bnp help

Can someone decipher how many and what the last nitro proof psi was. Confused since 2006 std looks less psi than previous.
What service pressure are they suggesting I use?
Thanks again

There are mm measurements on the corners that are blocked out of this pic( they still matched bore size today). Would also like to know the date of the oldest proof, that would let me know when the replacement barrels were made.
Will take what I can get. Thanks again

The original proof was 1904-1925 (chamber length is not marked) for the 16g standard service of 1 oz. in a 2 1/2" case (the 16 in the diamond would be over LC if 2 3/4")
The original bores were R 17/1 = .655" - .661" and L 16 = .662" - .668" and on reproof (Crown over R) marked in mm
It was reproved after the chambers were lengthened to 70 mm. The Proof House date code changed in 2005 and on the upper R of your image would be 2006
So it was proved to CIP standards of Max. Service 780 BAR or 11,313 psi; MSIP 900 BAR or 13,053 psi; and Proof 980 BAR or 14,214 psi.

Thank you very much.
I was shooting 6600 psi shells in it to be safe. Now will probably shoot anything with cip on the box that’s less than 1oz 1200fps.