I think JB hit on it when he mentions different types of varmints. For Ground Squirrels I like the .222, prairie dogs, I like the .204, For fur I like the .222 or a downloaded .223 or 223AI. For coyotes on up to deer sized varmints, I like the .223AI...If I had to pick an all-purpose varmint cartridge it would be the plain vanilla .223...hands down.
