If you are under the age of 21 and you want to use a handgun to hunt or for personal protection while hunting, you must possess a legal hunting license, be hunting during legal seasons in open areas, and not be trespassing (RCW 9.41.060 and 9.41.240).
Also, the handgun must meet appropriate requirements if you are using it for hunting. Big game, except for cougar, must be hunted using a handgun with a minimum barrel length of 4 inches, per the manufacturer’s specification, and it must fire a minimum .24 caliber centerfire cartridge. Cougar may be hunted with a .22 caliber centerfire handgun. Rimfire handguns are not legal for big game.
A modern handgun cannot be used to dispatch wounded game during archery or muzzleloader seasons.
Game birds cannot be hunted with a handgun or rifle, with the exception of blue grouse, spruce grouse, and ruffed grouse (WAC 232-12-047).
9th of November, 2015