The blowgun is said to date back to the stone age, used on all continents but Africa at the time. Archaeologists believe the blowgun evolved from a toy to a hunting tool over time. It was used to kill small animals and birds. Primitive blowguns were made from bamboo, cane, or any natural "tube." Any rings or bumps in the tube that would impede the projectile were burned or drilled out. Most modern blowguns are made out of metal and may have sights and mouthpieces
Blowgun darts can travel up to 400 feet per second. That's 2 times as fast as an arrow shot from a wooden bow. Blowgun pellets now come in .38, .40, .50, and .68 caliber. The .625 diameter "Big Bore" allows better air flow and therefor can shoot heavier calibers faster.
Blowguns were mainly used to kill small prey in close quarters. They are quieter than a bow and arrow and quicker. A dart (usually dipped in poison) or a pellet from a blowgun came to almost completely replace the bow and arrow in Southeast Asian jungle and forest hunting. Except for Renaissance Italy, however; the blowgun was not often used during combat.