Volume 18 of Professor Parabellum's Practical Scrap Metal Small Arms.

This volume provides plans and instructions for the creation of the "King Cobra .22", a strange 100% DIY rectangular-shaped firearm with three barrels that allows for maximum concealability. 

"Often falsely marketed as a clandestine U.S. Army weapon, the King Cobra is a three-shot .22 caliber firearm w h ich has been produced in illicit workshops in Thailand since at least the 1960s. Measuring 4" long, 1 3/4" wide and with a mere 1/2" thick body, it can be easily concealed within a cigarette carton or top pocket of a shirt. The design allows for three successive shots to be discharged using one hand giving it a clear edge ove rmost homemade weapons of this type. The mechanics of the gun are very basic and construction requires little more than a drill, hacksaw and steel plate."