If you are hitting the wires, you are then not quite extending properly with the bow. As you come out with the bow, try to avoid using your shoulder to move the bow downwards towards the tip. Instead, use more of your forearm to extend out which might feel uncomfortable at first. This should help you to stay within the brackets better and develop a more proper bow stroke. The other thing I recommend is watching yourself in the mirror to see exactly where you are going wrong.