bullet destroy on collison

after adding in the 'Destroy(gameObject);' line to destroy the bullet after colliding with a wall for example the enemy will not shoot. Any ideas as to why?

bullet script:

 var Dammage = 50;
 
 function OnCollisionEnter (info : Collision)
 {
     info.transform.SendMessage("ApplyDammage1", Dammage, 
     SendMessageOptions.DontRequireReceiver);
     Destroy(gameObject);
 }
 
 function Update () 
 {
     var translation : float = Time.deltaTime * 60;
     transform.Translate(0,0,translation);
 }
 

ai script:

 var Distance;
 var Target : Transform;
 var ShootRange = 25.0;
 var attackRange = 15.0;
 var moveSpeed = 5.0;
 var Damping = 6.0;
 var projectile : Rigidbody;
 var fireRate : float = 1;
 var FireRange = 0-100;
 private var nextFire : float = 0.0;
  
 function Update ()
 {
         Distance = Vector3.Distance(Target.position, transform.position);
        
         if (Distance < ShootRange)
         {
                 GetComponent.<Renderer>().material.color = Color.yellow;
                 lookAt();
         }
        
         if (Distance > ShootRange)
         {
                 lookAt();
                
         }
        
         if (Distance < attackRange)
         {
                 GetComponent.<Renderer>().material.color = Color.red;
                 attack ();
         }
        
         if (Distance > attackRange && Time.time > nextFire )
         {
         nextFire = Time.time + fireRate;
                 Instantiate(projectile, transform.position, transform.rotation);
                
         }
 }
  
 function lookAt ()
 {
         var rotation = Quaternion.LookRotation(Target.position - transform.position);
        
         transform.rotation = Quaternion.Slerp(transform.rotation, rotation, Time.deltaTime * Damping);
                        
        
        
 }
  
 function attack ()
 {
         transform.Translate(Vector3.forward * moveSpeed * Time.deltaTime);
 }