problem with lag

So Im making so that when the player shoots the enemies do as well, but b/c all of the rays being casted it lags, here's the code, how do I make it so that it can check for distance and if it's too far than it wont shoot the ray

code;

using UnityEngine;

public class EnemyShoot : MonoBehaviour
{

public float damage = 1f;
public float range = 100f;

public GameObject FpCam;
public ParticleSystem muzzle;

private Transform Thing;
private Transform player;

public float distanceAway = 500f;

void Update()
{
if (Input.GetButtonDown("Fire1")) {
Shoot();
//make it so that when the players position is farther from distanceAway it wont shoot
}
}

void Awake() {
Thing = this.transform;
player = GameObject.FindGameObjectWithTag("Player").transform;
}

void Shoot () {

muzzle.Play();
FindObjectOfType<AudioManager>().Play("Shoot");

RaycastHit hit;
if (Physics.Raycast(FpCam.transform.position, FpCam.transform.forward, out hit, range)) {
Debug.Log(hit.transform.name);

PlayerTarg target = hit.transform.GetComponent<PlayerTarg>();
if (target != null) {
target.PlayerDMG(damage);
}
}
}
}