How do I combine a void with an iteration?

Trying to make an fps and i need to combine an Iteration with a void:

using UnityEngine; using System.Collections;

public class Gun : MonoBehaviour {

 public float damage = 10f;
 public float range = 100f;
 public float fireRate = 15f;

 public int maxAmmo = 30;
 public int currentAmmo;
 public int bulletsLeft = 200;
 public float reloadTime = 1f;
 public AudioClip reload1;
 private bool isReloading = false;
 AudioSource audio;
 private bool playReloadSound = false;



 public Camera fpsCam;
 public ParticleSystem muzzleFlash;
 public GameObject impactEffect;

 private float nextTimeToFire = 0f;

 public Animator animator;

 void Start ()
 {
     currentAmmo = maxAmmo;
     audio = GetComponent<AudioSource>();
     animator.SetBool("Fire", false);
 }

 
 void Update () {
     if (isReloading)
         return;


     if (playReloadSound)
         audio.PlayOneShot(reload1);
         playReloadSound = false;


     if (currentAmmo <= 0)
     {
         StartCoroutine(Reload());
         return;
     }

     if (Input.GetButton("Fire1") && Time.time >= nextTimeToFire)
     {
         nextTimeToFire = Time.time + 1f / fireRate;
         StartCoroutine(Shoot());
         AudioSource shoot = GetComponent<AudioSource>();
         shoot.Play();

     }

     if (bulletsLeft <= 0) return;



 }

 IEnumerator Reload () //combine this
 {
     isReloading = true;
     Debug.Log("Reloading...");

     animator.SetBool("Reloading", true);

     playReloadSound = true;

     yield return new WaitForSeconds(reloadTime);

     animator.SetBool("Reloading", false);

     currentAmmo = maxAmmo;

     isReloading = false;
 }

 private void Reload2() //with this
 {
     if (bulletsLeft <= 0) return;

     int bulletsToLoad = maxAmmo - currentAmmo;
     int bulletsToDeduct = (bulletsLeft >= bulletsToLoad) ? bulletsToLoad : bulletsLeft;

     bulletsLeft -= bulletsToDeduct;
     currentAmmo += bulletsToDeduct;
 }

 IEnumerator Shoot()
 {
     muzzleFlash.Play();
     animator.SetBool("Fire", true);
     currentAmmo--;
     yield return new WaitForSeconds(0.05f);
     animator.SetBool("Fire", false);


     RaycastHit hit;
     if (Physics.Raycast(fpsCam.transform.position, fpsCam.transform.forward, out hit))
     {
         Debug.Log(hit.transform.name);

         Target target = hit.transform.GetComponent<Target> ();
         if (target != null) 
         {
             target.TakeDamage (damage);
         }

         GameObject impactGo = Instantiate(impactEffect, hit.point, Quaternion.LookRotation(hit.normal));
         Destroy(impactGo, 2f);
     }
 }
     

}