Is something wrong with my California Kingsnake?

Cal Kings can have a strong feeding response. I don't feed any of my snakes by hand. I only use tongs as they will nail your fingers every time. Defensive strikes to the hand aren't unusual and kingsnakes are known for aggressiveness. If you're feeding once a week, that should be sufficient. Kings are not my favorite species as they tend to be aggressive and when they aren't biting, they are musking or crapping on you. I've had a kingsnake for 3 years and he still musks and poops on you when you take him out. It's possible that your snake is going into shed and that tends to make them tense and aggressive as well. I suspect that he will be going into blue soon and after he sheds he'll go back to eating and won't be as aggressive. During the period of blue, make sure you bump up the humidity a bit by either misting the cage once a day, or offering a moist hide for him to go in. Also make sure that you have several hides so that he feels secure.