The Bureau of Alcohol, Tobacco, Firearms & Explosives will not allow transfer of ANY automatic weapon into Washington state since July 1, 1994 (except departmental purchases). Thus, there are no exceptions for antiques under Washington state law per RCW 9.41.190 and the definitions under RCW 9.41.010. Nevertheless, it is theoretically possible per Washington law to own an automatic weapon if you are in the armed forces, provided that BATFE will provide the $200.00 tax stamp.
RCW 9.41.190 states the following:
It is unlawful for any person to manufacture, own, buy, sell, loan, furnish, transport, or have in possession or under control, any machine gun or any part thereof capable of use or assembling or repairing any machine gun: Provided, however, That such limitation shall not apply to any peace officer in the discharge of official duty, or to any officer or member of the armed forces of the United States or the state of Washington: Provided,further, That this section does not apply to a person, including an employee of such person, who or which is exempt form or licensed under the National Firearms Act (26 U.S.C. section 5801 et seq.), and engaged in the production, manufacture or testing of weapons or equipment to be used or purchased by the armed forces of the United States, and having a United States government industrial security clearance.
See Washington State Attorney General Opinion.
If you are retired from the military, you may have to go to court and obtain a WRIT OF MANDAMUS (or a declaratory judgment- a legal determination of a court as to the legal position of litigants in cases where there is doubt as to their position in law) in order to get the stamp. A Writ of Mandamus orders officials to perform as required by law and is an extraordinary writ; i.e., a long shot where the BATFE’s decision on your application has been to deny the application. We wilI will be glad to draft an opinion letter as to the legal issues, litigation strategy and possible legal outcomes of any proposed litigation; e.g., pertaining to a WRIT OF MANDAMUS or potential declaratory judgment.
Opinion letters normally are limited to a well-defined purview (which will be stated in the letter) subject to certain disclaimers. The BATFE is notorious for changing its policies without notice especially when it comes to defining what makes certain weapons and parts for firearms legal. The definitions are published but subject to interpretation.
We have previously researched short-barreled shot guns and there are some like the Serbu Shorty, for example, that may be legal in Washington subject to getting a $5.00 stamp from the BATFE. Thus, there are many grey areas which are subject to interpretation but obtaining a legal opinion shows that you at least conducted your due diligence if you end up in court.