Weapon reload timer problem.

i tried to write a weapon fire script, that also has an automatic reload timer, it works well, shoots the bullets, substracts 1 ammunition, and then waits X seconds until it can fire again with the ammo reloaded. The problem is that when it reloaded and has X amount of bullets again, it wont substract anymore, so the second round is infinite. any ideas what i am doing wrong?

 using UnityEngine;
 using System.Collections;
 
 public class NewWeaponManager : MonoBehaviour {
 
     public GameObject parent;
     public GameObject muzzle;
     public Texture[] muzzleTexture;
     public Rigidbody bulletPrefab;
     public bool fireWeapon;
     public float velocity = 10.0f;
     public float weaponSpeed = 0.1f;            // Speed of weapon.
     public float weaponScattering = 0.005f;
     public bool isSpawning = false;
 
     public int currentAmmunition;
     public int maxAmmunition = 25;
 
     public bool muzzleFlashEnabled = false;
 
     public bool reloadWeapon = false;
 
     // Use this for initialization
     void Start () {
     
         currentAmmunition = maxAmmunition;
 
     }
     
     // Update is called once per frame
     void Update () {
 
         if (muzzleFlashEnabled == true) {
             muzzle.gameObject.SetActive(true);
         } else {
             muzzle.gameObject.SetActive(false);
         }
 
         if (currentAmmunition <= 0) {
             reloadWeapon = true;
             StartCoroutine (ReloadWeapon (5));
             CancelInvoke("SpawnBullet");
         }
 
         if (fireWeapon == true && isSpawning == false) {
             if (reloadWeapon == false) {
                 muzzleFlashEnabled = false;
                 isSpawning = true;
                 InvokeRepeating ("SpawnBullet", 0.001f, weaponSpeed);
             }
         } else if (fireWeapon == false) {
             muzzleFlashEnabled = false;
             CancelInvoke("SpawnBullet");
             isSpawning = false;
         }
     
     }
 
     void SpawnBullet() {
 
         muzzleFlashEnabled = true;
         float randomDirX = Random.Range (-weaponScattering, weaponScattering);
         float randomDirY = Random.Range (-weaponScattering, weaponScattering);
         Quaternion ScatterDirection = new Quaternion (transform.rotation.x + randomDirX, transform.rotation.y + randomDirY, transform.rotation.z, transform.rotation.w);
 
         currentAmmunition -= 1;
 
         Rigidbody newBullet = Instantiate(bulletPrefab, transform.position, ScatterDirection) as Rigidbody;
         newBullet.AddForce(transform.forward*velocity, ForceMode.VelocityChange);
         newBullet.GetComponent<Ammunition>().parentWeapon = gameObject;
 
     }
 
     public IEnumerator ReloadWeapon(float timer) {
         yield return new WaitForSeconds (timer);
         reloadWeapon = false;
         currentAmmunition = maxAmmunition;
     }
 }