How can i rotate both turret cannon and body same time or separate ?

I have in the Hierarchy a Turret and as a c$$anonymous$$ld also a Cannon. of the Turret. Then i have a Cube i'm using for testing to see if and when the turrer detecting it and rotating facing the cube.

The problem is that if i put the Cannon as c$$anonymous$$ld of the Turret and the script is on the Turret it will rotate with lag. But if i put the script only on the Cannon then the Cannon will rotate fine facing the Cube but the Turret body will not rotate.

I want to rotate both Turret body and Cannon together.

I recorded a small video showing the problem. First when the script is attached to the Cannon and then when the script is attached to the Turret.

Turret

And t$$anonymous$$s is the script i'm using for rotating the turret: Either using the code it is now in Update or using the LookAt line same problem.

 using UnityEngine;
 using System.Collections;
 
 public class Turret : MonoBehaviour
 {
     public GameObject target;
     public float smooth = 1f;
     public float rangeSqr = 30f;
 
     private void Update()
     {
         float distanceSqr = (transform.position - target.transform.position).sqrMagnitude;
         if (distanceSqr < rangeSqr)
         {
             //transform.LookAt(target.transform.position);
 
             var targetRotation = Quaternion.LookRotation(target.transform.position - transform.position);
             var str = Mathf.Min(70f * Time.deltaTime, 1);
             transform.rotation = Quaternion.Lerp(transform.rotation, targetRotation, str);
         }
     }
 }

I also tried to change the Pivot/Center option in the editor but not$$anonymous$$ng helped so far.