What shooting is arsenal using?

what shooting is arsenal using?
is it a raycast or a clone?

I don’t understand what you mean with clone, can you elaborate?

i mean a part that is cloned…

I highly doubt it’ll be cloning a part and moving it, that wouldn’t be a stable or efficient way to handle the shooting. I haven’t played that much so someone else might be able to confirm, but I’m almost certain 90% of the weapons are hitscan, which is simply raycasting and dealing damage instantly.

but when in three graphics there is a bullet trail

They can just use raycasting to know where to shoot, and then for visuals they can just smootly cover that distance with the bullet part.

This can be added in afterwards, since you already know the path of the bullet. The trail is a purely visual effect, but the raycast itself isn’t a physical object. For weapons where you can see the bullet travel before it hits, this is a combination of cframe, lerping and/or extra visual effects.

I’d recommend using the FastCast open-source module. You can use it straight away in your games, for free, or just read the code & use that to build your own knowledge and understanding.