How do I make headshots do more damage using raycast?

So I have a zombie, and it is the parent of a head model, just the head is tagged "Head", why doesnt this work? shooting the head should do more damage? Thanks (javascript):

 var DamageAmount : int = 5;
 var DamageAmountHead : int = 15;
 var TargetDistance : float;
 var AllowedRange : float = 400;
 
 function Update () {
     if (GlobalAmmo.LoadedAmmo >= 1) {
         if(Input.GetButtonDown("Fire1")) {
 
             var Shot : RaycastHit;
             if (Physics.Raycast (transform.position, transform.TransformDirection(Vector3.forward), Shot)) {
                 TargetDistance = Shot.distance;
                 if (TargetDistance <= AllowedRange &&  (Shot.collider.tag.Equals("Head"))) { 
                     Shot.transform.SendMessage("DeductPoints", DamageAmountHead, SendMessageOptions.DontRequireReceiver);
                 }
                 else  if (TargetDistance < AllowedRange) {
                  
                         Shot.transform.SendMessage("DeductPoints", DamageAmount, SendMessageOptions.DontRequireReceiver);
                     }
                 }
             }
         }
     }