I disagree. The barrel did not fail at the lug. The welds held.
First, I did not say the barrel failed
at the lug. And anyone looking at the photos can plainly see that the welds indeed failed - the lug is still held in the receiver while the barrel flew off....
The failure pattern is NOT indicative of barrel obstruction but of high pressure loads and/or even a double charge of powder. As the center line of the barrel began to split down thru the 6 sight holes, the barrel began to peel open....Barrel obstructions generally result in barrel bulges and/or splits at the muzzle end.
Obviously you did not read my post very closely before replying. This is exactly the type of damage seen from a barrel obstruction immediately ahead of the chamber. The bulged or "flowered" muzzle results from a plug at the muzzle. I've seen barrels blown by obstructions ahead of the chamber, like stuck bullets or cleaning rods. Yes, there are folks who fire a round with the cleaning rod still
in the barrel. My old range had several relics on the window ledge testifying to this.
We agree that what caused this damage was excessive chamber pressure, not a weak barrel. A weak barrel would have split only at the sight holes - this would have released normal pressures very quickly and would not have initiated additional damage. The fact that the barrel flowered at the chamber end and the lug separated from the barrel point to excessive bolt thrust and excessive radial pressure. Both are caused by excessive chamber pressure, either too much powder or a barrel obstruction. Since he claimed he used factory ammo and fired 37 shots without incident, the barrel obstruction explanation is the simplest and most likely.
Of course we will never know the whole story...
BTW, I've never had an issue with either my .45-70 or .50-70 Contender barrels, which have far less meat above the chambers than the puny .444 does. But I certainly don't load to factory .444 chamber pressures with either....