The gun forms vortex rings by forcing air or some other gas at high velocity down the gun’s cylinder. The ring forms when the friction of the cylinder wall causes a thin layer of the gas to roll forward on itself like a donut. Imagine a tornado formed into a donut shape. The ring revolves on itself while traveling out the cylinder and it can maintain that stability for long distances. Depending on the size of the gun, Battelle data confirms that a ring vortex can exit a generator at 90 miles per hour and maintain a speed of at least 60 mph for more than 50 yards.

Battelle: Battelle Develops Vortex Ring Gun for Firefighters, Pesticide Delivery.