RCW 9.41.190
Unlawful firearms — Exceptions.
(1) It is unlawful for any person to manufacture, own, buy, sell, loan, furnish, transport, or have in possession or under control, any machine gun, short-barreled shotgun, or short-barreled rifle; or any part designed and intended solely and exclusively for use in a machine gun, short-barreled shotgun, or short-barreled rifle, or in converting a weapon into a machine gun, short-barreled shotgun, or short-barreled rifle; or to assemble or repair any machine gun, short-barreled shotgun, or short-barreled rifle.
RCW 9.41.010
Terms defined.
Unless the context clearly requires otherwise, the definitions in this section apply throughout this chapter.
(1) "Firearm" means a weapon or device from which a projectile or projectiles may be fired by an explosive such as gunpowder.
(2) "Pistol" means any firearm with a barrel less than sixteen inches in length, or is designed to be held and fired by the use of a single hand.
(3) "Rifle" means a weapon designed or redesigned, made or remade, and intended to be fired from the shoulder and designed or redesigned, made or remade, and intended to use the energy of the explosive in a fixed metallic cartridge to fire only a single projectile through a rifled bore for each single pull of the trigger.
(4) "Short-barreled rifle" means a rifle having one or more barrels less than sixteen inches in length and any weapon made from a rifle by any means of modification if such modified weapon has an overall length of less than twenty-six inches.