It now transpires that the shooter that this issue refers to was new to black powder. Instead of reading the menu before starting to cook he jumped in with both feet and loaded with Accurate No.5 for God's sake. A double based smokeless powder.

Apparently, somewhere on the label it said "universal" so he thought it was all right to use it.

My only question would be "How did he get away so lightly?"

More information will follow as I get it.