Dynamite gun

A dynamite gun is any of a class of artillery pieces distinguished by their specialized operating mechanism and purpose: they use compressed air to propel an explosive projectile. Dynamite guns were in use for a brief period from the 1880s to the beginning of the twentieth century.

Because of the instability of early high explosives, it was impractical to fire an explosive-filled shell from a conventional gun. The violent deflagration of the propellant charge and the sudden acceleration of the shell would set off the explosive in the barrel of the gun. By using compressed air, the dynamite gun was able to accelerate the projectile more gradually through the length of the barrel. See Internal ballistics.

Guns for naval use were supplied with air from shipboard compressors. A small model for field use by land forces employed a powder charge to drive a piston down a cylinder, compressing air that was then fed into the gun barrel. This field model was famously used by Theodore Roosevelt's Rough Riders during the Spanish–American War, but had actually been used previously by Cuban insurgents against Spanish forces.