LeFusil. You have an economical memory because you did not bother to read your first post. I took exemption to " short sighted" and "ridiculous actually" also I can think what I like about your reply and I did not wish to know weather you think your reply was derogatory or not it is what I think in this case matters.
You also did not understand the 0.735 situation that I am sure is quite clear though I will repeat it more simple for you to understand because in the days of Damascus barrels and the use of plug gauges by the proof houses a gun could be entered for proof with a barrel measurement of 0.735 and it will be in proof BUT!! And this is where you could not comprehend the gun is proofed at the correct size 12 bore though the barrel only has five thousands of of metal that be removed before it goes out of proof rather than the ten thousands if its size was at the start 0.729.
I did not say that people over this side of the pond do not hone barrels you took that on board your self without my help.
Why cant you understand the the simple math that a 12 bore gun is in proof if its bore diameter is in the band between 0.729 and 0.739 that is simple enough and if it gets to 0.740 it is out of proof if as you say you are understanding British proof, though we both know now that you do not know the basic rules of proof at all because I intentionally left out the one measurement that is the corner stone of British proof and if you where as knowledgeable as you say you would have bust a gut to point it out but you didn't. So I will enlighten you ALL BRITISH GUN BARREL INTERNAL PROOF MEASUREMENTS ARE MADE NINE INCHES FROM THE BREACH FACE! I do not give lectures I just impart information in good faith though if that cap fits then wear it. it is your good self is making things difficult trying to score points out of things that are not there just of tour own making.
Finally I am sure you would wish to continue this until our Henty VIII would forgive Ann Boleyn for sleeping around. Finally I see you have a liking for Emoji's I will let the "British Archer from the battle of Agincourt give my final opinion.

[Linked Image from i.imgur.com]


The only lessons in my life I truly did learn from where the ones I paid for!