It’s tiny because the sphere has been scaled down, and the sphere’s transform contains that scaling. Why are you using a sphere? Ideally you’d use a marker/bone on the mesh, so that when the art changes, so does the projectile positioning. If you’re just using placeholder meshes, and would rather just having a component for it, I would try using a Scene Component instead. That way you can leave the scale at 1.0,1.0,1.0 and use the transform directly. Though, I guess then you can’t debug render it. Or just break the sphere transform, and make a new transform with the sphere’s location and rotation and a 1.0,1.0,1.0 scale.
But back to your original problem. Everything in your blueprints look fine to me. I’d start looking for other places that the projectile might be getting offset. Is the box component at 0,0,0 local space inside the projectile? Is there anything in the projectile blueprint that’s moving it? Are there any offsets in the projectile’s details? Do any other blueprints reference/adjust the projectile?
If you can strip down your project to just the blueprints you need for this (maybe exporting your character to a new project?), and post a sample project, someone might be able to find the problem somewhere.