Help with SendMessage?

I’m trying to use SendMessage to tell an object that it has been hit by a ray. Basically, I have two attacks. I have a short hit and a long hit, each need to do different damage. How do I send the amount of damage that it needs to apply to the receiver?

Lets say your receiver have a Damage function with a float parameter

void Damage(float damageValue){

     hp -= damangeValue;


Then on the other side, when the raycast hit the object then Call the SendMessage function

float damangeValue = 10f;

RaycastHit hit;

if(Physics.Raycast(gun.position, gun.forward, out hit, rayDistance)){
     hit.collider.gameObject.SendMessage("Damage", damangeValue);