if (Input.GetButton("Fire1") && Time.time >= nextTimeToFire)
            {

                nextTimeToFire = Time.time + 1f / fireRate;
                cam.transform.Rotate(1, 0, 0);

            }

================================================================================================

using UnityEngine;
using System.Collections;
using UnityEngine.Networking;

[AddComponentMenu("Camera-Control/Mouse Look")]
public class camMouseLook : NetworkBehaviour
{

    public enum RotationAxes { MouseXAndY = 0, MouseX = 1, MouseY = 2 }
    public RotationAxes axes = RotationAxes.MouseXAndY;
    public float sensitivityX = 15F;
    public float sensitivityY = 15F;

    public float minimumX = -360F;
    public float maximumX = 360F;

    public float minimumY = -60F;
    public float maximumY = 60F;

    public float fireRate = 15f;

    private float nextTimeToFire = 0f;

    float rotationY = 0F;

    Rigidbody rb;
    public Camera cam;

    void Update()
    {
        if (!isLocalPlayer) return;
        {
            if (axes == RotationAxes.MouseXAndY)
            {
                float rotationX = transform.localEulerAngles.y + Input.GetAxisRaw("Mouse X") * sensitivityX;

                rotationY += Input.GetAxisRaw("Mouse Y") * sensitivityY;
                rotationY = Mathf.Clamp(rotationY, minimumY, maximumY);

                transform.Rotate(0, Input.GetAxisRaw("Mouse X") * sensitivityX, 0);
                cam.transform.localEulerAngles = new Vector3(-rotationY, 0);
            }
            else if (axes == RotationAxes.MouseX)
            {
                transform.Rotate(0, Input.GetAxisRaw("Mouse X") * sensitivityX, 0);
            }
            else
            {
                rotationY += Input.GetAxisRaw("Mouse Y") * sensitivityY;
                rotationY = Mathf.Clamp(rotationY, minimumY, maximumY);

                transform.localEulerAngles = new Vector3(-rotationY, transform.localEulerAngles.y, 0);
            }

            if (Input.GetButton("Fire1") && Time.time >= nextTimeToFire)
            {

                nextTimeToFire = Time.time + 1f / fireRate;
                cam.transform.Rotate(1, 0, 0);

            }
        }
    }

    void Start()
    {
        // Make the rigid body not change rotation
        if (rb)
            rb.freezeRotation = true;
        rb = GetComponent<Rigidbody>();
    }
}