Someone told GhostGunner that our new fascist law specifically bans polymer 80% lowers/frames.  They currently are not allowing any sales of polymer/metallic lowers/frames to Washington residents.  Their lawyer might allow metallic sales again, after he interprets our laws.

IANAL, but this sounds like they got bad advice that caused them to pull sales:

RCW 9.41.010 Terms defined.
(11) "Firearm" means a weapon or device from which a projectile or projectiles may be fired by an explosive such as gunpowder. "Firearm" does not include a flare gun or other pyrotechnic visual distress signaling device, or a powder-actuated tool or other device designed solely to be used for construction purposes.
33) "Undetectable firearm" means any firearm that is not as detectable as 3.7 ounces of 17-4 PH stainless steel by walk-through metal detectors or magnetometers commonly used at airports or any firearm where the barrel, the slide or cylinder, or the frame or receiver of the firearm would not generate an image that accurately depicts the shape of the part when examined by the types of X-ray machines commonly used at airports.

My Glock barrel and slide weigh over 15 oz.

Am I missing anything?

My understand is they're legal.   Cabelas in Lacey sells complete polymer 80 pistols.  As far as in know they're not functionally different than a polymer 80 you compete yourself.  I doubt Cabelas would be selling undetectable firearms.  

Plus there are retailers, including some in Washington,  that still sell p80 receives to Washington residents.

Many companies  are afraid to sell in Washington because of RCW 9.41.325, which makes it illegal to aid a person in manufacturing an untraceable or undetectable firearms.  Since they can't do a background check on an unfinished receiver, it just easier to not sell in Washington,  rather then deal with Bob Ferguson suing them.

Not to mention parts kits.. a few places don't sell us parts kits if it includes full auto parts.
Some places out right just say no shipping to WA.  
Places like Bowman would remove the bolt unless they mail the the bolt kit to a FFL.
There are other places that still mail to WA.

I bought a g17 80 at rainier arms a few months ago...

Their lawyer probably didn't read how Washington defines a firearm.  It's different than the federal definition.    In Washington a firearm has to be able to fire a projectile.  The polymer lower can't fire a projectile.  

For background check purposes, WA even says in RCW 9.41.111.  The logical conclusion from how WA defines a firearm and the fact that the legislature acknowledge federal definitions of a frame or receiver, implies that a polymer 80 is legal.  

Centerfiresystems won't even sell ar15 lower parts kits to WA now because it's a "firearms parts kit" and  that company has now gone full retard.

I heard of a guy that's bought a couple of them from Big Daddy Unlimited, shipped them to his house in WA no problem.  Pretty sure they're cheaper through them than anywhere else too.  

Rainier Arms also sells them, and you can buy them there with cash, which has obvious benefits (more secure than having your credit card/data stolen by nefarious persons).