This gun might pass proof 'as is' for light loads, such as RST's. It might be worthwhile to send it over the pond to have proofed and if it passes, great, if not, have something else done such as teague, sleeve, etc and ship back home??
Thing is they put a proof load through what the chamber is opened to......there is no reproof with a requested marshmallow load.......that would be too easy
Truth is, we need to have a person on here that has worked at a proofhouse that measures barrels for a living to give us his take. 12" from breech is a lot different from 9" from breech which is "point of proof" where bore dia is measured. Every measurement from there is from breech end forward. But if the walls are anywhere near 20 thou at 12" that's right where your hands are. My waif 2 lb 4 oz barrels on my 20 ga Boss measure 32-35 thou there and 50 thou at 9" from breech....so something is amiss here
Until someone with "the Knowledge" of Proof from UK steps up and offers his insight based on measurements of thousands of guns based on current Rules of Proof, most of this pontification here is just that... hot air
