Old documents can be real treasures.
A couple years ago I read that the bunker penetration capability of cruise missiles was increased by adding a shaped charge to their nose that opens a hole in and weakens the structure. The principle has since been applied to warheads with "follow-through" function. Everytime I read about such a warhead the reports make it sound as if it was a great feat of engineering.
Now imagine my astonishment when I saw this
edit: Better try this volume.