What is the waiting period in Washington State?

The FBI no longer allows courtesy NICS check for handguns to WA residents. 

All pistol transfer applications are sent to local law enforcement for approval. This can take 10-30 days. If you are purchasing an SAR(Semi-automatic Rifle) it will also go to a local law enforcement for approval with a mandatory 10 business day wait period per I-1639.

Lower receivers, shotguns, bolt action rifles, and all other firearms are still run through the NICS system. In most cases, you can take home the same day if approved.