[SOLVED]Get variable of an object that creates different object with a script

Hey guys again,

I am really sorry to ask maybe stupid question but I am struggling with this for a long time. I've searched through forums and answers but cant find my exact problem.

I have got a tower(gameObject) with a script where I can drag and drop bullet prefab with a bullet script.

How can I get a reference to a variable from Tower.script to Bullet.script ? Tower.script instantiates bullets which fly to target and I want to tell every bullet what dmg it should take to the enemy.

Keep in mind that I want to create many towers and every tower is upgradeable so dmg will change based on every upgrade of the tower.

Static variable is not an option and GetComponent works if script are on the same gameobject or child object (bullets are independent gameobjects). FindObject method is slow and wont work coz of many levels of towers. The only moment they have something in common is when bullet gameobject with a script is dropped in tower.script .

Maybe I am missing something or is there different use from these options?

Tower.script

 // shoot next bullet?
         timeLeft -= Time.deltaTime;
         if (timeLeft <= 0.0f) {
             // find the closest target (if any)
             Unit target = findClosestTarget();
             if (target != null) {        
                 // is it close enough?
                 if (Vector3.Distance(transform.position, target.transform.position) <= range) {
                     // spawn bullet
                     GameObject g = (GameObject)Instantiate(bulletPrefab.gameObject, transform.position, Quaternion.identity);
                     // get access to bullet component
                     Bullet b = g.GetComponent<Bullet>();
                     
                     // set destination        
                     b.setDestination(target.transform);
                     
                     // reset time
                     timeLeft = fireRate;
                 }
             }
         }

Bullet.script

         // was target reached?
         if (transform.position.Equals(destination.position)) {
 
             Unit t = destination.GetComponent<Unit>();
 
             if (t != null) 
             {
 
             t.health = t.health - 1 (tower.dmg should be here);
             
             // unit elimination
             if (t.health <= 0)
                 t.onDeath();
             }
             
             // destroy bullet
             Destroy(gameObject);
         }