Game Object Layer changes automatically on runtime.,Game Object's Layer automatically changes in runtime?

1. I set a prefab object known as "Armor" and set its layer to "default"

2. I click the play button...

3. The "Armor" layer then changes to "weapon" instead of default

Question: Why does the armor's layer changes on runtime? I want to keep it the layer as it is and not change it during runtime.

 using UnityEngine;
 using UnityEngine.Networking;
 using System.Collections;
 
 public class WeaponManager : NetworkBehaviour {
 
     [SerializeField]
     private string weaponLayerName = "Weapon";
 
     [SerializeField]
     private Transform weaponHolder;
 
     [SerializeField]
     private PlayerWeapon primaryWeapon;
 
     private PlayerWeapon currentWeapon;
     private WeaponGraphics currentGraphics;
 
     public bool isReloading = false;
 
     void Start ()
     {
         EquipWeapon(primaryWeapon);
         weaponLayerName = "Default";
     }
 
     public PlayerWeapon GetCurrentWeapon ()
     {
         return currentWeapon;
     }
 
     public WeaponGraphics GetCurrentGraphics()
     {
         return currentGraphics;
     }
 
     void EquipWeapon (PlayerWeapon _weapon)
     {
         currentWeapon = _weapon;
 
         GameObject _weaponIns = (GameObject)Instantiate(_weapon.graphics, weaponHolder.position, weaponHolder.rotation);
         _weaponIns.transform.SetParent(weaponHolder);
 
         currentGraphics = _weaponIns.GetComponent<WeaponGraphics>();
         if (currentGraphics == null)
             Debug.LogError("No WeaponGraphics component on the weapon object: " + _weaponIns.name);
 
         if (isLocalPlayer)
             Util.SetLayerRecursively(_weaponIns, LayerMask.NameToLayer(weaponLayerName));
 
     }
 }

,Ok so the I set a game object's layer (as prefab) to default. Then when I tested the game during runtime it changes the layer name from default to "weapon" for no reason.

The layer name "weapon" is what I made for gun objects but other objects seem to change the layer name to "weapon" instead of setting up as "default". Any fixes to this?

 using UnityEngine;
 using UnityEngine.Networking;
 using System.Collections;
 
 public class WeaponManager : NetworkBehaviour {
 
     [SerializeField]
     private string weaponLayerName = "Weapon";
 
     [SerializeField]
     private Transform weaponHolder;
 
     [SerializeField]
     private PlayerWeapon primaryWeapon;
 
     private PlayerWeapon currentWeapon;
     private WeaponGraphics currentGraphics;
 
     public bool isReloading = false;
 
     void Start ()
     {
         EquipWeapon(primaryWeapon);
         weaponLayerName = "Default";
     }
 
     public PlayerWeapon GetCurrentWeapon ()
     {
         return currentWeapon;
     }
 
     public WeaponGraphics GetCurrentGraphics()
     {
         return currentGraphics;
     }
 
     void EquipWeapon (PlayerWeapon _weapon)
     {
         currentWeapon = _weapon;
 
         GameObject _weaponIns = (GameObject)Instantiate(_weapon.graphics, weaponHolder.position, weaponHolder.rotation);
         _weaponIns.transform.SetParent(weaponHolder);
 
         currentGraphics = _weaponIns.GetComponent<WeaponGraphics>();
         if (currentGraphics == null)
             Debug.LogError("No WeaponGraphics component on the weapon object: " + _weaponIns.name);
 
         if (isLocalPlayer)
             Util.SetLayerRecursively(_weaponIns, LayerMask.NameToLayer(weaponLayerName));
 
     }