Pete got those images from auctions on eBay. I asked both sellers how the cracks occurred. The top image seller never responded. The second image seller claimed he was shooting 2 3/4" #4 duck loads. Neither seller would provide serial numbers. Both failures have been discussed in depth on the board.
I purchased a Philadelphia Sterlingworth, that on close examination had a crack visible internally. I had it welded and only shoot low pressure loads in it. If I want to go goose hunting, I use a Baikal o/u with 3" chambers. It is cheap and strong as can be expected. It will digest 3" shells all day long (or until my shoulder surrenders). If I want to hunt grouse, I take the 16ga Sterlingworth with 2 1/2" #8's.
Pete
