i need help with a gun recoil script

This is the script but can not get it when you shoot a small setback to repeat each time you shoot is done. the script works 100%

using UnityEngine; using System.Collections; using UltraReal.Utilities; using UltraReal.WeaponSystem;

///
/// Basic launcher class. This would be your gun script. /// public class BasicLauncher : UltraRealLauncherBase {

 /// <summary> 
 /// Time before the next shot can be fired.
 /// </summary>
 float _nextShotTime;

 /// <summary> 
 /// keeps track of the current ammo count before a reload is requred.
 /// </summary>
 int _ammoCount;

 /// <summary> 
 /// Time delay before next shot can be fired.  A machine gun would use a really small shot delay.
 /// </summary>
 [SerializeField] 
 private float _shotDelay = 0.1f;

 /// <summary> 
 /// How long it takes to reload the wepaon.
 /// </summary>
 [SerializeField]
 private float _reloadDelay = 1f;

 /// <summary> 
 /// The amount of ammo a magazine(clip) can hold.
 /// </summary>
 [SerializeField]
 private int _magazineSize = 20;

 /// <summary> 
 /// Reference to the Transform for the shell ejector.
 /// </summary>
 [SerializeField]
 private Transform _ejectorTransform = null;

 /// <summary> 
 /// Reference to the Transform for the muzzle position.
 /// </summary>
 [SerializeField]
 private Transform _muzzleTransform = null;

 /// <summary> 
 /// Reference to the AudoClip for reloading.
 /// </summary>
 [SerializeField]
 private AudioClip _reloadSound = null;

 
 /// <summary> 
 /// Reference to the AudoClip for missfiring.
 /// </summary>
 [SerializeField]
 private AudioClip _missfireSound = null;

 /// <summary> 
 /// Force applied to ejected shells.
 /// </summary>
 [SerializeField]
 protected float _ejectorForce = 100f;

 /// <summary> 
 /// Torque applied to ejected shells.
 /// </summary>
 [SerializeField]
 protected float _ejectorTorque = 100f;

 /// <summary> 
 /// Reference to the AudioSource for the gun.  If it's null, it will create one.
 /// </summary>
 [SerializeField]
 protected AudioSource _audioSource = null;

 /// <summary> 
 /// Reference to animator for the shooting, and reloading
 /// </summary>
 [SerializeField]
 protected Animator _animator = null;

 /// <summary> 
 /// Name of the trigger in the animation controller for Firing.
 /// </summary>
 [SerializeField]
 protected string _fireAnimTriggerName = "Fire";

 /// <summary> 
 /// Name of the trigger in the animation controller for Reloading.
 /// </summary>
 [SerializeField]
 protected string _reloadAnimTriggerName = "Reload";

 /// <summary> 
 ///    Sets defaults for weapon
 /// </summary>
 protected override void OnStart ()
 {
     base.OnStart ();

     _nextShotTime = Time.time;
     _ammoCount = _magazineSize;

     if (_audioSource == null)
         _audioSource = gameObject.AddComponent<AudioSource>();
 }

 /// <summary> 
 ///    Fires the weapon
 /// </summary>
 public override void Fire ()
 {
     if (_nextShotTime <= Time.time){
         if (_ammoCount > 0 && _ammo != null) {

             if(_muzzleTransform != null)
                 _ammo.SpawnAmmo(_muzzleTransform, _ejectorTransform, _ejectorForce, _ejectorTorque, 2f, _audioSource);

             _ammoCount--;

             if (_animator != null)
                 _animator.SetTrigger(_fireAnimTriggerName);

             base.Fire ();
         }
         else
             MissFire();
         _nextShotTime = Time.time + _shotDelay;
     }
 }

 /// <summary> 
 ///    Forces a weapon missfire.
 /// </summary>
 public override void MissFire()
 {
     base.MissFire ();

     if (_missfireSound != null && _audioSource != null)
         _audioSource.PlayOneShot (_missfireSound);
 }

 /// <summary> 
 /// Reloads the weapon
 /// </summary>
 public override void Reload ()
 {
     base.Reload ();

     if (_reloadSound != null && _audioSource != null)
         _audioSource.PlayOneShot (_reloadSound);

     if (_animator != null)
         _animator.SetTrigger(_reloadAnimTriggerName);

     _nextShotTime = Time.time + _reloadDelay;
     _ammoCount = _magazineSize;
 }

} thanks :)