Thanks Gary for that memory... You know that does make sense about the damage to barrels. In remembering those movies they always have a sheet of flame going out of the barrel. And this is before the golden age of special effects. So to capture the flash they had to do it the old fashion way by overloading the blank. I remember reading some where that the wagon itself, was on display outside at universal studios for a while, but only being made of wood I can not imagine that lasted long.
It would be a fun job to figure out what the actual weight of the wagon would be if it was made out of armor plate.