• Zips, Pipes, This homemade single-shot 32 pistol is equipped with a suppressor made from a modified garden tractor muffler. The weapon is fired by the spring-release trigger bar. ( Courtesy ofBATFJ eighteen month, $3 million covert research program called 'Project Naomi/ the arsenal included dart guns . . . light bulbs and automobile engine parts that emit poison gas Bizarre weaponry. . . . umbrella guns, silent guns Somber-faced legislators were duly photographed pointing dart guns or looking with suitable dread at a bottle of shellfish poison.