No, this Ruger Mark IV Target model is a No for WA state due to the threaded barrel.

Hi Andres, unfortunately no. A semi-auto pistol cannot have a threaded barrel, which this model does.
budsgunshop.com/feeds/state_reg/washington_restrictions.pdf ,
This model has a non-threaded barrel and is WA state legal budsgunshop.com/product_info.php/products_id/22347/ruger+mark+iv+target+blued+22+long+rifle+pistol ,
Stay safe & have a great day!

H Andres and welcome. No Sir, the "Threaded Barrel" is restricted on a Semi-Auto pistol currently in the State of Washington. Cheers, stay safe and enjoy! Details under "Assault Weapons" - vi here: budsgunshop.com/feeds/state_reg/washington_restrictions.pdf

It is legal however you must be 21 and have a valid CCL "Handguns:
To purchase a handgun in the state of Washington, a person must be minimum age 21, a
resident of the state, and must possess a valid concealed pistol license. Additionally, the
transferring dealer must be notified in writing by the chief of police or sheriff of a jurisdiction in
which the purchaser resides that the purchaser is eligible to possess a pistol under RCW
9.41.040." budsgunshop.com/feeds/state_reg/washington_restrictions.pdf />