Why can't my Physics.Raycast work

I'm making 2D games (well, i'm really new), and I use this UnityScript code (frankly speaking, it's from the tutorial) inside a gun sprite without collider in (0,0,0). I put some objects with box collider next to the gun (around (5,0,0)). When I click the mouse, the "shoot shoot!" shows up in the log, but the shootHit.point doesn't. I have set every layer but the gun as "Shootable" and no result yet.

Could anyone tell me why?

 #pragma strict
 var fireSpeed : float = 0.4f;
 var range : float = 100f;
 
 private var timer : float;
 private var shootRay : Ray;
 private var shootHit : RaycastHit;
 private var shootableMask : int;
 
 function Awake () {
     shootableMask = LayerMask.GetMask("Shootable");
 }
 
 function Update () {
     timer += Time.deltaTime;
     
     if(Input.GetButton("Fire1") && timer >= fireSpeed){
         Shoot();
     }
 }
 
 function Shoot () {
     timer = 0f;
     
     Debug.Log("shoot shoot!");
     
     shootRay.origin = transform.position;
     shootRay.direction = transform.right;
     
     if(Physics.Raycast(shootRay, shootHit, range, shootableMask)){
         Debug.Log(shootHit.point);    
     }
 }