Shooting script,I can shot in Y axis ,

Hello , i'm doing my first shooter game , but when I use my script I can't shot in the Y.-Y axis(up and down) the bullets are not following my direction, any information can help to solve it.

using UnityEngine; using System.Collections;

public class Disparos : MonoBehaviour {

 public GameObject balaOriginal;

 public float vel;

 public GameObject puntoSpawn;


 // Use this for initialization
 void Start()
 {

 }

 // Update is called once per frame
 void Update()
 {
     //Che input
     if (Input.GetKeyDown(KeyCode.Mouse0))
     {
         //Disparar
         LanzarProyectil();


     }
 }
 void LanzarProyectil()

 { //obtener referenia del clon recien creado
     GameObject nuevaBala;
     nuevaBala = (GameObject)Instantiate(balaOriginal,puntoSpawn.transform.position,this.transform.rotation);


     //Objeter la referencia de su  Rigibody
     Rigidbody rigidDelClon;
     rigidDelClon = nuevaBala.GetComponent<Rigidbody>();

     //Dar velocidad
     rigidDelClon.velocity = transform.forward * vel;
                             

 }

},Hello , I'm doing my first shooter game, I make this fo shooting but I can't shot in Y and -Y axis, (up and dow ), if I shot in other directions it follows correctly.

using UnityEngine; using System.Collections;

public class Disparos : MonoBehaviour {

 public GameObject balaOriginal;

 public float vel;

 public GameObject puntoSpawn;


 // Use this for initialization
 void Start()
 {

 }

 // Update is called once per frame
 void Update()
 {
     //Che input
     if (Input.GetKeyDown(KeyCode.Mouse0))
     {
         //Shot
         LanzarProyectil();


     }
 }
 void LanzarProyectil()

 { //Clon Ref
     GameObject nuevaBala;
     nuevaBala = (GameObject)Instantiate(balaOriginal,puntoSpawn.transform.position,this.transform.rotation);


     //Rigibody Ref
     Rigidbody rigidDelClon;
     rigidDelClon = nuevaBala.GetComponent<Rigidbody>();

     //Give Speed .                                                                                                                        rigidDelClon.velocity = transform.forward * vel;
                             

 }

}