The rifle in the link is a .300 WM built by Sako. It appears that the damage is a result of poor metalurgy. I've seen similar results from hotshots that think that they can ignore reloading safety or that they are real armorers and really don't know what they are doing... According to the thread, the shooter was not seriously injured... how, I have no idea. This will really give you the proverbial pucker factor...
Mike
http://www.benchrest.com/forums/showthread.php?t=17626
Mike
http://www.benchrest.com/forums/showthread.php?t=17626