ray and projectile

hi , i made a third person shooter , i used ray hit and made a projectile , the only problem is that my ray hit register before the projectile get`s to target

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class FPSShooterTut : MonoBehaviour
 {
     public Camera cam;
     public GameObject projectile;
     public Transform FirePoint;
     public float projectileSpeed = 30;
     private Vector3 destination;
     private float timeToFire;
     public float fireRate = 10;
     public float damage = 10f;
     public float impactDelay = 5f;
     public float arcRange = 1;
     void Start()
     {
         
     }
 
     // Update is called once per frame
     void Update()
     {
         if (Input.GetButton("Fire1") && Time.time >= timeToFire)
         {
             timeToFire = Time.time + 1/fireRate;
             ShootProjectile();
         }
     }
     void ShootProjectile()
     {
         
         Ray ray = cam.ViewportPointToRay(new Vector3(0.5f, 0.5f, 0));
         
         RaycastHit hit;
         
         if (Physics.Raycast(ray, out hit))
             
         destination = hit.point;
         
 
 
 
 
 
         else
             destination = ray.GetPoint(1000);
        
 
         InstantiateProjectile(FirePoint);
 
 
 
         Debug.Log(hit.transform.name);
         
 
 
 
     }
     void InstantiateProjectile(Transform firePoint)
     {
         var projectileObj = Instantiate(projectile, firePoint.position, Quaternion.identity) as GameObject;
         projectileObj.GetComponent<Rigidbody>().velocity = (destination - firePoint.position).normalized * projectileSpeed;
         iTween.PunchPosition(projectileObj, new Vector3(Random.Range(-arcRange, arcRange), Random.Range(-arcRange, arcRange), 0), Random.Range(0.5f, 2));
        
 
     }
 }