What term refers to a device or combination of devices that was not originally a firearm but adapted to expel a projectile through a smooth-bore or rifled-bore barrel by using the energy generated by an explosion or burning substance?

• A. Zip Gun
• B. Derringer
• C. Pistol
• D. Revolver

Answer: (A)

The key idea is an improvised firearm—something not designed as a gun from the start, put together from non-firearm parts to fire a projectile using the energy from an explosion or burning propellant. That concept fits the term “zip gun,” which refers to crude, homemade devices assembled to shoot a cartridge through a barrel, whether smooth or rifled. The other terms describe firearms that were originally manufactured as firearms (a small, concealable pistol; a general term for handguns; and a revolver with a rotating cylinder), so they don’t capture the improvised, non-originally-weapon nature described here.