Changes to gun laws in Washington State become law on July 1.
In 2018 voters approved initiative 1639 that among other changes makes it illegal for anyone under 21-years-old to buy a semiautomatic rifle. New provisions that take effect on Monday, July 1 include enhanced background checks and waiting period requirements for the purchase and transfer of rifles.
The law also requires specific training before a rifle can be purchased. The Range in Yakima is now offering a I-1639 rifle certification classes to help people obtain a special certificate that is required for purchase. Along with that requirement there's also a 10 day waiting period and new storage requirements.
Under the measure, stores that sell guns are required to give or sell the gun buyer a gun storage device like a trigger lock.

Retailers that sell firearms is required to display a warning sign in block letters that reads;

WARNING: YOU MAY FACE CRIMINAL PROSECUTION IF YOU STORE OR LEAVE AN UNSECURED FIREARM WHERE A PERSON WHO IS PROHIBITED FROM POSSESSING FIREARMS CAN AND DOES OBTAIN POSSESSION.
The new provisions take effect on Monday, July 1.