How can the ammo go to 31 at the start of a game?,How can I make The current ammo return to 31 at the start of a game?

Can't you just assign it in Start(), like :

  using UnityEngine;
  public class Gun : MonoBehaviour {
  
      [Header("References")]
      [SerializeField] private GunData gunData;
      [SerializeField] private Transform cam;
      [SerializeField] private Transform R_Bullet;
      public GameObject Bullet_Emitter;
      public GameObject Bullet;
      public float Bullet_Forward_Force;
      
      float timeSinceLastShot;
  
      private void Start() {
          PlayerShoot.shootInput += Shoot;
          PlayerShoot.reloadInput += StartReload;
          gunData.currentAmmo = 31; //This is the line you need to add
      }
  
      private void OnDisable() => gunData.reloading = false;
  
      public void StartReload() {
          if (!gunData.reloading && this.gameObject.activeSelf)
              StartCoroutine(Reload());
      }
  
      private IEnumerator Reload() {
          gunData.reloading = true;
  
          yield return new WaitForSeconds(gunData.reloadTime);
  
          gunData.currentAmmo = gunData.magSize;
  
          gunData.reloading = false;
      }
  
      private bool CanShoot() => !gunData.reloading && timeSinceLastShot > 1f / (gunData.fireRate / 60f);
  
      private void Shoot() {
          if (gunData.currentAmmo > 0) {
              if (CanShoot()) {
                  if (Physics.Raycast(cam.position, cam.forward, out RaycastHit hitInfo, gunData.maxDistance)){
                      IDamageable damageable = hitInfo.transform.GetComponent<IDamageable>();
                      damageable?.TakeDamage(gunData.damage);
  
                      GameObject Temporary_Bullet_Handler;
                      Temporary_Bullet_Handler = Instantiate(Bullet,Bullet_Emitter.transform.position,Bullet_Emitter.transform.rotation) as GameObject;
                      Temporary_Bullet_Handler.transform.Rotate(Vector3.left * 180);
                      Rigidbody Temporary_RigidBody;
                      Temporary_RigidBody = Temporary_Bullet_Handler.GetComponent<Rigidbody>();
                      Temporary_RigidBody.AddForce(transform.forward * Bullet_Forward_Force);
                      Destroy(Temporary_Bullet_Handler, 10.0f);
  
                  }
  
                  gunData.currentAmmo--;
                  timeSinceLastShot = 0;
                  OnGunShot();
              }
          }
      }
  
      private void Update() {
          timeSinceLastShot += Time.deltaTime;
  
          Debug.DrawRay(cam.position, cam.forward * gunData.maxDistance);
      }
  
      private void OnGunShot() {  }
  }