I read many pages since the last time I posted, but the mention of British proof caused me to wake up. British proof is ridiculous and useless. The Brits make thin wall guns at their factories and shade tree British gunsmiths grind them out to be even thinner. The Brits will pass a .008 gun as long as it doesn't blow up when testing it. It is a crazy, useless, government excuse to tax. US proof would be even worse, with a minimum wall thickness of .150 with a sliding scale to make it .180 by the year 2030.