Excellent post, lagopus--and that's what those of us who know something about the system in the UK would prefer to see. As opposed to--for example--guns and ammunition regulated by OSHA.
For those that have never heard of unobstructed guns failing for one reason or another, you just haven't been around long enough, or haven't been paying attention. Used to be a guy named Greg Tag who hung around here. He was into Ithacas, and one of his interests was keeping track of frame failures on Flues models, especially the light 20's. He had a few of those documented. Then there are the Bell tests, reported in DGJ. Yes, he used extreme overloads--but the barrels were not obstructed, and they did blow.
And Craig . . . no, I didn't stick 2 3/4" shells in a gun with 2 1/2" chambers. My first introduction to a firearm was my dad's Eastern Arms .410 single shot, which I still have. (Front bead gone, forend taped to the barrel.) It started life as a 2 1/2" gun. When the 3" shells appeared, what was the solution? Some gunsmith lengthened the chamber to 3", and voila. I had the same "surgery" performed on a pre-war Sauer 16. That was long before the existence of doublegunshop, even predated Al Gore's invention of the Internet. AND IT STILL HAPPENS--in spite of our best efforts here (and some of us, like myself, in print publications) to keep it from happening.
Gunsmiths that go to the doublegun school run by Dennis Potter and other experienced doublegun smiths know darned well that you don't punch chambers on short-chambered guns. Unfortunately, that is but a small % of the people in this country who hang out their shingle as a gunsmith. And only a small % of the people who own doubles read this website, or DGJ, or Shooting Sportsman, or other places where they're likely to get good information rather than copious amounts of BS.
But hey, if you want to leave everything in the hands of trial lawyers . . . yeah right. Like that's a rock solid, conservative position.
