removing an int after random use

Yeah idk how to work with break or return but for my semi randomized game i need it to pick out a random number do it then disable it, to reload is pressed(i already have the randomized and doing stuff working)her it is. using System.Collections; using System.Collections.Generic; using UnityEngine;

 public class RandomizedGun : MonoBehaviour
 {
     public GameObject bulletPrefab;
     public Transform gunbody;
     public GameObject hiteffect;
     public Transform player;
     public GameObject medkitPrefab;
     public Transform Mag;
 
     public float bulletForce = 20f;
 
     System.Random rand = new System.Random();
     int gun;
 
     void Update()
     {
         if (Input.GetButtonDown("Fire1"))
         {
             gun = rand.Next(1, 7);
             if (gun == 1)
             {
                 Shoot1();
             }
             else if (gun == 2)
             {
                 Shoot1();
             }
             else if (gun == 3)
             {
                 Shoot1();
             }
             else if (gun == 4)
             {
                 Shoot2();
             }
             else if (gun == 5)
             {
                 Shoot1();
             }
             else if (gun == 6)
             {
                 Shoot3();
             }
         }
     }
     void Shoot1()
     {
         GameObject bullet = Instantiate(bulletPrefab, gunbody.position, gunbody.rotation);
         Rigidbody2D rb = bullet.GetComponent<Rigidbody2D>();
         rb.AddForce(gunbody.up * bulletForce, ForceMode2D.Impulse);
     }
     void Shoot2()
     {
         GameObject effect = Instantiate(hiteffect, Mag.position, Quaternion.identity);
         Destroy(effect, 1f);
     }
     void Shoot3()
     {
         GameObject medkit = Instantiate(medkitPrefab, gunbody.position, gunbody.rotation);
         Rigidbody2D rb2 = medkit.GetComponent<Rigidbody2D>();
         rb2.AddForce(gunbody.up * bulletForce, ForceMode2D.Impulse);
     }
 }