Since I was standing there with JoeinCharlotte when the remains of the gun were brought in, I'll put in my 2 cents worth too.
I've been going to the VGC and other SxS shoots since 2008, and this is the first blow-up at one of those events that I'm aware of.
The shooter was borrowing the gun from another member of the shooting squad. After calling for the target, the shooter said the next thing he remembered was everyone asking him if he was OK.
The gun came back to the tent area with both hammers down and it could not be opened. Nobody was sure if both barrels had gone off or not. The 2nd barrel was checked with a cleaning rod and found to contain an empty shell, so both went off in quick succession.
There was much insistence and agreement among the squad of shooters that the shooter was using factory ammo. I did not get a chance, or think to, check the remaining ammo in the box to see if the shells appeared to be factory fresh or reloads. I have no reason to doubt the word of those shooters.
Looking at the pictures, that screw hole does seem deep and wide and well into the chamber wall of the other barrel. The Parker hammer guns with the dolls head extension all have that screw to secure the steel piece of the extension and rib. I double checked mine and it has that screw too. I have to wonder if what we see in the picture is what was correct for the factory, or if it was bored-out or deepened during a repair.
Everyone who saw the gun was thankful and amazed that nobody was injured and walked away shaking their head, and probably thinking something along the lines of "There but for the grace of God go I". I know I did. We all know that Damascus barrels are generally very strong, but you can't be too cavalier about what you put in them. The ammo still have to be appropriate for the gun.
Can't agree with JoeinCharlotte enough that this may well have been preventable. If you borrow a gun, always ask if your ammo is appropriate for the gun. If you lend a gun, make sure appropriate ammo is going to be used in it. And if you see something that looks amiss to you, say something.
---Matt
