Enemy health not reducing on collision with bullet

have different weapons, with one i would like to shoot real bullets, so i attached these two scripts to the bullet, but only the first works. are they interfering?

 using UnityEngine; using System.Collections;
 
 public class proj_giocatore_distruggi : MonoBehaviour {
  // Use this for initialization
  void Start () {
  
  }
  
  // Update is called once per frame
  void OnCollisionEnter (Collision collision) {
      GameObject prefab = Resources.Load ("esplosione") as GameObject;
      GameObject esplosione = Instantiate (prefab) as GameObject;
      esplosione.transform.position = transform.position;
  
      Destroy (esplosione, 2);
      Destroy (gameObject);
  }

}

////This is the second script

 using UnityEngine; using System.Collections;
 
 public class danno_proj_giocatore : MonoBehaviour { 
 
 public int danno = 100; 
 
 
 // Use this for initialization
 
  void Start () {
  }
  
  void OnTriggerEnter(Collider Other)
  {
      //Is colliding object a player? Cannot collide with enemies
      if (!Other.CompareTag ("enemy"))
          return;
      
  
      
      //Get PlayerController object and update cash
      Enemy_Drone EN = Other.gameObject.GetComponent<Enemy_Drone> ();
      
      //If there is a PC attached to colliding object, then update cash
      if (EN)
                      EN.Health += danno;
      
  
  }    
  

}