DivideByZero Expection: Division by zero?

 using UnityEngine;
 using System.Collections;
 
 public class WeaponShoot : MonoBehaviour {
     public PlayerWeapon[] Weapons;
 
 
     AudioSource audiosource;
 
     private RaycastHit hit;
     private bool Firing = false;
     private bool Reloading = false;
     private PlayerWeapon curWeapon;
 
     public float recoil = 50f;
     public AudioClip shoot;
 
 
 
     void Awake()
     {
         ChangeWeaponToSlot (0);
         audiosource = GetComponent<AudioSource> ();
     }
     void Update()
     {
 
         if(Input.GetKeyDown(KeyCode.R) && !Reloading)
         {
             StartCoroutine(isReloading());
         }
         else if (Input.GetButton("Fire1") && !Firing)
         {
             StartCoroutine(isFiring());
         }
 
 
     }
 
     void shot () {
 
         Vector3 myTransform = transform.transform.forward;
         Physics.Raycast (transform.position, myTransform, out hit, 50);
         if ((Physics.Raycast (transform.position, myTransform, out hit, 50)) && (hit.collider.gameObject.tag == ("Enemy")))
         {
             hit.collider.SendMessageUpwards("DoDamage");
             Debug.Log ("hit");
         }
     }
     private IEnumerator isFiring()
     {
         
         float rateOfFirePerSecond = 1 / (curWeapon.fireRate / 60);
         Firing = true;
         Camera.main.transform.Rotate( recoil * Time.deltaTime, 0, 0 );
 
         while (Input.GetMouseButton(0) && curWeapon.CurAmmo > 0)
         {
             Fire();
             yield return new WaitForSeconds(rateOfFirePerSecond);
         }
         Firing = false;
     }
 
 
     private IEnumerator isReloading ()
     {
         float reloadTimePerBullet = curWeapon.ReloadTime / curWeapon.AmmoMax;
         Reloading = true;
 
         while (curWeapon.AmmoMax > 0 && curWeapon.CurAmmo < curWeapon.ClipSize)
         {
             Reload();
             yield return new WaitForSeconds(reloadTimePerBullet);
         }
         Reloading = false;
     }
 
 
     void Fire()
     {
         Vector3 forwardLocal = transform.forward;
 
 
         if ((Physics.Raycast(transform.position, forwardLocal, out hit, 50)) && (hit.collider.gameObject.tag == ("enemy")))
         {
             hit.collider.GetComponent<AiHealthScript>().DoDamage(curWeapon.Damage);
         }
 
 
         audiosource.PlayOneShot(curWeapon.GunShot, 0.7f);
         curWeapon.CurAmmo--;
     }
 
 
     void Reload()
     {
         curWeapon.AmmoMax--;
         curWeapon.CurAmmo++;
     }
 
 
     void ChangeWeaponToSlot(int index)
     {
         if(Weapons.Length > index)
         {
             curWeapon = Weapons[index];
         }
     }
 
 
 }

whenever i run my game and try to hit an enemy it gives me this error: DivideByZero Expection: Division by zero