Does anyone know how i can learn to make high quality guns?

I understand ray-casting and CFrame animation. i understand how to use roblox plugin animations. so i know how to make a basic gun on roblox.

But how do i make a more professional gun. one that has a cross hair that expands when moving and shooting. a gun that has animations while running, jumping and aiming. maybe a gun that ejects shells per shot and uses a hitscan or projectile mechanic instead of raycasting.

I don't want any scripts (obviously) i just want to know if anyone has a video tutorial or if a tutorial is in a coding book. or if there is a plugin for it.