Not only have I seen a couple, I have studied this, as much as can be done outside of a laboratory. I sincerely doubt that this is fake. There is a double handful of "mistakes" that can cause this, wrong powder, wrong primer, overload, under load, sometimes the phase of the moon, of course one of my favorites, brother in law. I see it most often in rifles. From barrels split completely from the muzzle to the receiver, to barrels ejected completely off of the rifle. First, and anyone who has shot or reloaded has heard this before, DO NOT shoot someone elses reloads. I know your brother in law is directly descended from Daniel Boone, Jeff Cooper and Elmer Keith. He's still an idiot. Second, when shooting prairie dogs in Wyoming in July do not leave your ammo on the hood of the truck. Hot ammo can raise pressures dramatically. Third, if something sounds funny, look down the barrel, yes unload the gun first. Two weeks ago I had in the shop a .22 rimfire that split the barrel extension and the receiver, ammo problem. It happens, rarely. Our firearms are safe, normally there's a loose nut behind the trigger.
