my lives system is buggy

so i made a unity lives counter so that when the player gets hit buy the enemy bullet he decrease a live but sometimes it works and often doesnt sometimes it reloads the level and sometimes it counts as 2 bullets hit in the same time my player have a rigidbody and 2 capsule collider one isTriggered and one is not triggered here is my cowboy(player) script :

using System; using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEngine.SceneManagement;

public class Cowboy : MonoBehaviour {

 public float walkSpeed = 2.5f;
 public float jumpHeight = 5f;

 public Transform groundCheckTransform;
 public float groundCheckRadius = 0.2f;

 public Transform targetTransform;
 public LayerMask mouseAimMask;
 public LayerMask groundMask;

 public GameObject bulletPrefab;
 public Transform muzzleTransform;


 public AnimationCurve recoilCurve;
 public float recoilDuration = 0.25f;
 public float recoilMaxRotation = 45f;
 public Transform rightLowerArm;
 public Transform rightHand;
 public float Magazines = 5f;
 public int lives;
 

 private float inputMovement;
 private Animator animator;
 private Rigidbody rbody;
 private bool isGrounded;
 private Camera mainCamera;
 private float recoilTimer;
 private bool resetGame;
 private string collisionObject;
 

 private int FacingSign
 {
     get
     {
         
         Vector3 perp = Vector3.Cross(transform.forward, Vector3.forward);
         float dir = Vector3.Dot(perp, transform.up);
         return dir > 0f ? -1 : dir < 0f ? 1 : 0;
     }
 }

 void Start()
 {
     animator = GetComponent<Animator>();
     rbody = GetComponent<Rigidbody>();
     mainCamera = Camera.main;
     lives = 3;
 }

 [Obsolete]
 void Update()
 {
     if(lives < 1)
     {
         Application.LoadLevel(Application.loadedLevel);
     }
     //gets Z input
     inputMovement = Input.GetAxis("Horizontal");

     Ray ray = mainCamera.ScreenPointToRay(Input.mousePosition);
     RaycastHit hit;

     if (Physics.Raycast(ray, out hit, Mathf.Infinity, mouseAimMask))
     {
         targetTransform.position = hit.point;
     }
     // gets Space input
     if (Input.GetButtonDown("Jump") && isGrounded)
     {
         rbody.velocity = new Vector3(rbody.velocity.x, 0, 0);
         rbody.AddForce(Vector3.up * Mathf.Sqrt(jumpHeight * -1 * Physics.gravity.y), ForceMode.VelocityChange);
     }
     // gets mouse input
     if (Input.GetButtonDown("Fire1"))
     {
         if (Magazines > 0){
             Fire();
         }
         
     }
     
     
 }

 private void Fire()
 {

     //Fire a bullet
     recoilTimer = Time.time;
     var go = Instantiate(bulletPrefab);
     go.transform.position = muzzleTransform.position;
     var bullet = go.GetComponent<Bullet>();
     bullet.Fire(go.transform.position, muzzleTransform.eulerAngles, gameObject.layer);
     Magazines--;
 }

 private void LateUpdate()
 {
     // Recoil Animation
     if (recoilTimer < 0)
     {
         return;
     }

     float curveTime = (Time.time - recoilTimer) / recoilDuration;
     if (curveTime > 1f)
     {
         recoilTimer = -1;
     }
     else
     {
         rightLowerArm.Rotate(Vector3.forward, recoilCurve.Evaluate(curveTime) * recoilMaxRotation, Space.Self);
     }


 }

 private void FixedUpdate()
 {
     // Movement
     rbody.velocity = new Vector3(inputMovement * walkSpeed, rbody.velocity.y, 0);
     animator.SetFloat("speed", (FacingSign * rbody.velocity.x) / walkSpeed);

     // Facing Rotation
     rbody.MoveRotation(Quaternion.Euler(new Vector3(0, 90 * Mathf.Sign(targetTransform.position.x - transform.position.x), 0)));

     // Ground Check
     isGrounded = Physics.CheckSphere(groundCheckTransform.position, groundCheckRadius, groundMask, QueryTriggerInteraction.Ignore);
     animator.SetBool("isGrounded", isGrounded);
 }

 private void OnAnimatorIK()
 {
     // Weapon Aim at Target IK
     animator.SetIKPositionWeight(AvatarIKGoal.RightHand, 1);
     animator.SetIKPosition(AvatarIKGoal.RightHand, targetTransform.position);

     // Look at target IK
     animator.SetLookAtWeight(1);
     animator.SetLookAtPosition(targetTransform.position);
 }

 [Obsolete]
 void OnTriggerEnter(Collider other)
 {
     // Get Bullet magazine 
     if (other.gameObject.layer == 8)
     {
         other.gameObject.SetActive(false);
         Magazines += 5;
     }
     //Die and respawn when fall out of world
     if(other.gameObject.layer == 9)
     {
         Application.LoadLevel(Application.loadedLevel);
     }
     if(other.gameObject.layer == 11)
     {
         lives--;
     }
 }

}

and here is my Bullet script :

using System; using System.Collections; using System.Collections.Generic; using UnityEngine.SceneManagement; using UnityEngine;

public class Bullet : MonoBehaviour { public float velocity = 20f; public float life = 1f;

 private int firedByLayer;
 private float lifeTimer;

 void Update()
 {

     RaycastHit hit;

     if (Physics.Raycast(transform.position, transform.forward, out hit, velocity * Time.deltaTime, ~(1<< firedByLayer)))
     {
         transform.position = hit.point;
         Vector3 reflected = Vector3.Reflect(transform.forward, hit.normal);
         Vector3 direction = transform.forward;
         Vector3 vop = Vector3.ProjectOnPlane(reflected, Vector3.forward);
         transform.forward = vop;
         transform.rotation = Quaternion.LookRotation(vop, Vector3.forward);
         Hit(transform.position, direction, reflected, hit.collider);
     }
     else
     {
         transform.Translate(Vector3.forward * velocity * Time.deltaTime);
     }

     if (Time.time > lifeTimer + life)
     {
         Destroy(gameObject);
     }
 }
 private void Hit(Vector3 position, Vector3 direction, Vector3 reflected, Collider collider)
 {
     // Do something here with the object that was hit (collider), e.g. collider.gameObject 
     Destroy(gameObject);
     
     
 }

 public void Fire(Vector3 position, Vector3 euler, int layer)
 {
     lifeTimer = Time.time;
     transform.position = position;
     transform.eulerAngles = euler;
     transform.position = new Vector3(transform.position.x, transform.position.y, 0);
     Vector3 vop = Vector3.ProjectOnPlane(transform.forward, Vector3.forward);
     transform.forward = vop;
     transform.rotation = Quaternion.LookRotation(vop, Vector3.forward);

 }
 void OnTriggerEnter(Collider other)
 {
     // Get Bullet magazine 
     if (other.gameObject.layer == 7)
     {
         Destroy(gameObject);
     }
     
 }
 }

i dont know what to do :(