This discussion reminds me of a guy named Foggy who made a rifle that was supposed to reach 5,000 feet per second, using a necked-down .30-06 case and shooting a .22 caliber 40 grain bullet. He supposedly put a lock on the bolt, so it wouldn't open, and loaded the case full of "machine gun powder". This was in Solon, Maine.
He claimed that when he fired the rifle, loaded with "machine gun powder" the bullet decintegrated and splattered in the trees behind his building. I contend that the powder didn't burn adequately and that's what may have spattered into the leaves. That is, if he wasn't just making up the whole story. It's amazing what people will come up with, isn't it.