A bone-stock Remington 770 in .270Win, shooting factory Remington ammunition, managed to demolish the last foot or so of barrel. Apparently the young man firing it had purchased rifle and ammo together, taken it to the range without so much as cleaning it first, and on its second shot ever, the gun grenaded.
Bore obstruction? Nope, else it would have detonated on the first shot. Squib? Apparently not; by all accounts the first shot sounded and felt normal. Probably just a fluke bad gun. It happens. Remington should buy him a new one and send him a nice letter and some ammo, and they'll probably have a happy customer.
An interesting internet phenomenon is to be found in the comments at the YouTube video. Just like on the gun boards, note all the people who come out and froth "I has a Remminton770 in .300 ought 6 and I shot 30000 shots through it and aint nevr nothign happend your a lire!"
Relax, Sparky, the guy wasn't saying anything about your gun. I'm sure yours is the bestest gun in the world.