Zach, Bud's will not ship this gun to WA, it is prohibited. The pistol grip, adjustable stock, threaded barrel, muzzle device, and barrel shroud are all prohibited in WA.
Details here budsgunshop.com/feeds/state_reg/washington_restrictions.pdf ,
If you order a gun that is WA compliant, Bud's will remove any non-compliant magazines.

The magazine isn't what will prevent this from being shipped to WA state. You would need a "Featureless" model.
No pistol grip
No adjustable stock
No threaded barrel
No muzzle flash Hider
Yeah, it's a bummer, sorry...
So, if you find one that is WA compliant Bud's would remove the higher capacity mags not Legal for your state.

Hi Zach and welcome. They will just not include the magazine Sir. This has been Bud's policy. However, laws have changed in the State of Washington for the worst. Details under Rifles here : budsgunshop.com/feeds/state_reg/washington_restrictions.pdf ------------- Cheers and stay safe!