If they are using a nontox shot or steel to load proof loads then they have altered the test beyond any reasonable test for these old doubles to pass. Why on Earth would anyone decide to test with steel? Has the proof house suffered a serious drop in IQ?
The entire reason for the test is to assure guns pass a reasonable standard test. For years we have deemed a gun safe to shoot, with the correct loads, if it passed proof and was in proof. Never considered shoot loads that by their very nature would cause major damage to my gun. And I never thought a Proof house would do it without major disclosure and fair warning. Shoot steel loads in a tight choked gun and you will soon have major barrel damage unless you can repeal the laws of physics. This is either unthinkable or unbelievable and I am not doubting the charge or the messenger.