 The dart, usually .50 caliber (12.7 mm), is essentially a ballistic syringe loaded with an immobilizing drug and hypodermic needle and is propelled from the gun by means of compressed gas.In flight, the dart is stabilized by a tailpiece, a tuft of fibrous material, making it behave somewhat like a badminton shuttlecock.The same syringe design may be used interchangeably in certain blowguns.