Definitely check that your ramp flap actually pokes under the cutaway in the orbit guide, I’ve seen more than one that don’tNot sure if common but my right orbit has always been horribly rattly. I've had this conversation with @robotgreg as his is pretty much the same. I've tried adjusting a few things but it's never made a huge difference, I just put it down to a bad design. I'll have to try the ramp flap.
Occasional shots will still rattle obviously if it’s not a clean shot but I managed to improve mine by a massive amount.