Just to expand on a few points raised. Here in the U.K. proof is not quite mandatory. If I made a gun and didn't have it Proofed then that is my choice but it would be an offence if I sold, offered for sale or exported it. That's to protect the other fellow and fair enough. All guns imported here into the U.K for onward sale have to pass through one or other of the Proof Houses unless Proofed in a Country that has an accaptable proof system; those Countries are Austria, Belgium, Chile, Czeckoslovakia, France, Germany, Finland, Hungary, Ireland, Italy, Spain and Yougoslavia. If I bought a gun from the U.S. and wanted it for my own use then I would not require to submit it to a Proof House until I wanted to sell it or, ironically, wanted to send it back from whence it came. As for the mention of the Winchester model 12 then that can be left unrestricted as a multi shot repeater but would need to be held on a Firearm Certificate same as a rifle. If restricted to just three shots then it is can be held on a Shotgun Certificate. If a gun is an interesting example such as one with an unusual patent action then it can legally be sold 'out of proof' if the Proof House issue a Certificate of Unprovability or Proof Exemption Certificate and the gun can then be sold provided that the certificate goes with it. This is so that unusual and interesting guns of some historical significance can be sold and collected.
I would not advocate the tyre test as that may just weaken it so that the next shot does burst it. The Proof Master has considerable experience of both eye and sensitive measuring apperatus to check everything is in order after the proof test has been conducted before he stamps it. The tyre test is akin to having someone with a work related first aid certificate being allowed to perform open heart surgery. We have had a Proof House here since 1637 so I guess they have learned a thing or two in that time and it has served us well so far. Lagopus.....
