One of my uncles did that with one of the first birdshead vaqueros, he was uninjured in the event. He was using reloads and he did not even realize what had happened at first. He tried to cock the hammer and he could not. That is when he realized that the whole topstrap was gone, and both chamebers to the left and right were busted off. It looked very similar to the picture in the thread. He claimed it was a problem with metallurgy, but Ruger felt it was probably a double charge. Anyway they replaced it but he quickly sold the replacement.