Would a rejected from GB proof house pass another countries proof I wonder? In other words are they over enforcing the rules while other proof house are not. Over here many states have yearly vehicle inspections and some testers are easier than others. In the end most avoid the too tough testers. Might be the same thing with proof testing. Market will adjust to what works best for them not the tester. Send a failed gun to the Spanish proof house and see if it passes. There might be a regional bias against passing British guns there and there might not be. Be a heck of a thing if it passed there but not at home.