Wait a sec. I think I see one of the problems here. To wit: unless I'm very much mistaken, the Bracketing function has NOTHING to do with Continuous or Single Shot. They are separate systems. When you choose Bracketing (including the menu option of how many stops of light you want the bracketing to cover, and whether you want AE, WB, or ADL brackets), the camera processes each shot three times and merges them for you to see. It does NOT take three shots in quick succession, merging them afterwards. Therefore, it has no effect on any of your Continuous or Single shot choices. Again: they are separate systems. One will not have any effect on the other.
I am really having trouble still, however, wrapping my head around your previous assertion that "I know it shoots 5 frames because there are 5 photos." So...you were able to time yourself holding the shutter button for exactly one second? That's how you know? Honestly, that just doesn't make sense. Did you press the button, at which time it took 5 frames and then stopped? Is that what you're saying? That's an extremely confusing sentence you wrote.
Oh well. As long as you are otherwise happy with your camera and this is just of academic interest, as you say, then it's pretty much a moot point, right? Just enjoy thinking your own D5500 is faster than specs say it should be!