Question Problem with sync direction a bullet that having a force

So currently working on TPS game that a playercan shoot a bullet to direction of mouse position.
But i got problem that direction of bullet is wrong like this



Here code PlayerController that handling player movement and shooting

Code (CSharp):

1. void Update()
2.     {
3.  
4.         if (!photonView.IsMine)
5.         {
6.             //gun.SetActive(false);
7.             return;
8.         }
9.  
10.         if (ratefire > 0f)
11.         {
12.             ratefire = ratefire - Time.deltaTime;
13.         }
14.  
15.         gunPos = gun.transform.position;
16.         gunRot = gun.transform.rotation;
17.  
18.         cameraRay = Camera.main.ScreenPointToRay(Input.mousePosition);
19.  
20.         if (Physics.Raycast(cameraRay, out cameraRayHit))
21.         {
22.             if (Input.GetMouseButtonDown(0) && myPV.IsMine)
23.             {
24.                 if(ratefire <= 0f)
25.                 {
26.                     GetComponent<PhotonView>().RPC("ShotGun", RpcTarget.AllBuffered);
27.                     ratefire = 0.5f;
28.                 }
29.             }

Code (CSharp):

1. [PunRPC]
2.  
3.     private void ShotGun()
4.     {
5.         Vector3 targetPos = new Vector3(cameraRayHit.point.x, transform.position.y, cameraRayHit.point.z);
6.         transform.LookAt(targetPos);
7.         audioSource.PlayOneShot(gunshotSound);
8.         GameObject _bullet = Instantiate(bullet, gun.transform.position, Quaternion.identity) as GameObject;
9.         Rigidbody rb_bullet = _bullet.GetComponent<Rigidbody>();
10.         //rb_bullet.AddForce(gun.transform.forward * 1000f);
11.         rb_bullet.AddForce(this.transform.forward * 1000f);
12.         Destroy(_bullet,1f);
13.     }
14.  
15.     #region IPunObservable implementation
16.  
17.     public void OnPhotonSerializeView(PhotonStream stream, PhotonMessageInfo info)
18.     {
19.         if (stream.IsWriting)
20.         {
21.             stream.SendNext(this.healthPoint);
22.             stream.SendNext(this.isGrounded);
23.             stream.SendNext(this.wasGrounded);
24.             stream.SendNext(this.gunPos);
25.             stream.SendNext(this.gunRot);
26.             stream.SendNext(this.targetPos);
27.         }
28.         else
29.         {
30.             this.healthPoint = (float)stream.ReceiveNext();
31.             this.isGrounded = (bool)stream.ReceiveNext();
32.             this.wasGrounded = (bool)stream.ReceiveNext();
33.             this.gunPos = (Vector3)stream.ReceiveNext();
34.             this.gunRot = (Quaternion)stream.ReceiveNext();
35.             this.targetPos = (Vector3)stream.ReceiveNext();
36.         }
37.     }
38.  
39.     #endregion

So first i try to shot bullet to direction forward of Player. Is still wrong. Then i try to using empty object "gun" then send position and rotation with OnPhotonSerializeView is still same. Any idea why and how to fix it? Thank you