If your going to be processing chickens I would recommend not getting into the habit of using a .22 to kill them. Those little .22s are just too unsafe due to ricochets. Darn little bullets will ricochet off of anything and turn angles you didn’t think possible. I’d just pick one of the methods mentioned in the above posts that works best for you, much safer that way, and you can save your .22 ammo for the squirrels. 
