And no a Washingtonian can't shoot a privately owned full auto - you can own one but you'll have to drive South or East to shoot it.
A correction is needed here.
Here is the text of the law:
RCW 9.41.190:
(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.
(2) This section shall not apply to:
(a) Any peace officer in the discharge of official duty or traveling to or from official duty, or to any officer or member of the armed forces of the United States or the state of Washington in the discharge of official duty or traveling to or from official duty; or
(b)
A person, including an employee of such person if the employee has undergone fingerprinting and a background check, who or which is exempt from or licensed under federal law, and engaged in the production, manufacture, repair, or testing of machine guns, short-barreled shotguns, or short-barreled rifles:
(i) To be used or purchased by the armed forces of the United States;
(ii) To be used or purchased by federal, state, county, or municipal law enforcement agencies; or
(iii) For exportation in compliance with all applicable federal laws and regulations.
(3) It shall be an affirmative defense to a prosecution brought under this section that the machine gun, short-barreled shotgun, or short-barreled rifle was acquired prior to July 1, 1994, and is possessed in compliance with federal law.
(4) Any person violating this section is guilty of a class C felony.
And, here's RCW 9.41.220:
All machine guns, short-barreled shotguns, or short-barreled rifles, 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, illegally held or illegally possessed are hereby declared to be contraband, and it shall be the duty of all peace officers, and/or any officer or member of the armed forces of the United States or the state of Washington, to seize said machine gun, short-barreled shotgun, or short-barreled rifle, or parts thereof, wherever and whenever found.
So, unfortunately, private citizens (yes, even police officers) can not own full auto here.