Originally Posted by nheninge
The barrel looks to be intact no bulge, no obstruction. An obstructed barrel would cause a very different explosion and would not explain why the base of the case blew out. It was a remington stock gun with factory remington ammo. The gun was shooting off the bench at a range and previous shots were fine and the round immediately preceding went bang with no hint of problems. Everything is going back to remington. I agree that the problem seems to be with this single round (wrong powder, spiked). I just wanted to see if anyone had an issue like this before or could at least tell me what exactly happened according to the laws of pressure.
On another note, I had the polymer tips falling off a box of winchester 7mm silvertips. Unexplained flyers were suddenly explained. Never shot factory ammo again. Likely never will again.
You are a lucky s.o.b.. I've only personally saeen this once with factory ammo and never with handloads. Back when I was in high-school I was at the local range and some poor guy was sighting in his 243 with fed. ammo. Next thing you know he's asking for help getting his action open. Same crap with blown open primer cup and brass damn near fused to the action. Never heard what happened afterward.
To get that kind of failure you'd have to be somewhere between 80 and 100 KPSI, roundabout anyway.