Federal law defines a machine gun as: [A]ny weapon which shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger. The term shall also include the frame or receiver of any such weapon, any part designed and intended solely and exclusively, or combination of parts designed and intended, for use in converting a weapon into a machine gun, and any combination of parts from which a machine gun can be assembled if such parts are in the possession or under the control of a person. Before you can transfer a lawfully owned machine gun, the gun must be registered with, and you must obtain a permit from, the Bureau of Alcohol, Tobacco, Firearms, and Explosives (“ATF”). There is usually a $200 excise tax to transfer a machine gun. You must also obtain ATF approval before engaging in the interstate transport of a machine gun. Before taking any weapon to another state – including a lawfully owned machine gun or assault weapon -- you should check to make sure the weapon is legal in such other states. Many states – including California – have weapons laws that are more restrictive than Nevada's.