How do i add different types of bullets in Unreal Engine 5's First Person Template

Hi! I am currently experimenting with the first person tamplate of unreal engine 5.
I was trying to add multiple guns with different types of bullets. But i couldn’t find a way to make it work. I used the basic pre-made rifle as a parent-class for the new gun. I also made the basic yellow projectile and the weapon component parent-classes. I want to make the new gun shoot a new type of projectile with an entirely new mesh.
I turned some values into variables to speed up the creation process.

Here are a view screenshots from my code:

Where do you set BulletType?

The bullet type is the basic yellow projectile by default.
I was thinking about how to solve my problem and i realised that i don’t know how the projectile, the rifle, the character and the weapon component are connected to each other.
I am currently tying to find the connection between the weapon component and the rifle. I wanted the weapon component as a parent-class for different weapon-componenst for different types of weapons.
I think when i find the link between the two that i can complete the code by my self.
If you know how to add multiple weapon components that work with specific weapons, please tell me how.

If you can get a reference to your gun, you should be able to change its BulletType. I am not too familiar with the First Person Template.

I’m trying to cast from BP_BaseGun to BP_Bullet but it doesn’t work for some reason.
What am i doing wrong? Can someone please explain what makes the cast fail?