How can i make the right choice of implementation of my shooting fire script ?

This is working but the way i'm doing it is wrong. I don't want to use not frame counts but rate of fire that is setup to be governed by the desired delay between shots in actual time.

I also want to make some bar i can move and change while the game is running the rate of fire. For example 10 bullets per second or 11 bullets per second or 200. I think the real one is 10 bullets per second but i want to be able to change it while the game is running. Something like this line: [Range(0f,20f)] public float bulletsPerSecond = 10f;

Not sure how to do it.

The first script is attached to the weapon that fire. The second script is attached to the bullet prefab i created. I have a Rigidbody component already on the weapon.

This is my script:

 using UnityEngine;
 using System.Collections;
 
 public class Shooter : MonoBehaviour {
 
     public GameObject bullet = null;
     public float bulletSpeed = 500f;
 
     private int frames = 0;
 
     void Update ()
     {
         frames++;
         if (frames % 10 == 0)
         {
             if (Input.GetKeyDown(KeyCode.G) || Input.GetKey(KeyCode.G))
             {
                 GameObject shot = (GameObject)Instantiate(bullet, transform.position
                     + (transform.forward * 2), transform.rotation);
 
                 Rigidbody _rigidbody = shot.AddComponent<Rigidbody>();
                 _rigidbody.AddForce(transform.forward * bulletSpeed);
             }
         }
     }
 }
 

And this is the script that destroy the bullets:

 using UnityEngine;
 using System.Collections;
 
 public class Bullet : MonoBehaviour {
 
     void OnCollisionEnter(Collision c)
     {
         Destroy(gameObject);
     }
 }