Could you give me some help? (About projectile)

[Gina]

Skript ver: 2.4
Mincraft ver: 1.12.2

I was making a skript about gun which shoots stone button, but the effects when button hits the entity doesn't work and also reloading system doesn't work too. I need some feedback and help to fix my code.

On Load:
    set {ammo} to 20
    
command /gun:
    trigger:
        give 1 of paper named "&6gun" with lore "&fright click - shoot" to player
        
on right click:
    if name of player's tool contains "&6gun":
        if {ammo} is 0:
            wait 3 seconds
            set {ammo} to 20
        else:
            make player shoot an item projectile of stone button at speed 5
            wait 0.3 seconds
            reduce {ammo} by 1
            
on projectile hit:
    if event-projectile is stone button:
        damage entity by 3 hearts
        delete event-projectile

 

[ESW_ST33le]

try that, i dont know if it will work but it might

on projectile hit:
    if event-projectile is stone button:
        damage victim by 3 hearts
        delete event-projectile

and for reloading use

on right click:
    if name of player's tool contains "&6gun":
        if {ammo} < 1:
            wait 3 seconds
            set {ammo} to 20