I recall that the Tornado F3 was 810 kts KIAS when we started, but very quickly the engineers stopped that. The jet would jet up to that speed at 250 ft level.
In a previous life I flew the mighty F4. Despite all off it's limitations the Brit F4 was fast,very fast. As a JP on one of my first exercises I did a high speed stern on some USAF F4s who were doing 480kts at low level. In full AB doing a slack decending turn the speed got a little high. As I glanced inside I noticed we were a good bit over 800 kts, and that was with the Sgt Fletchers on. Yes, and before you ask, the tanks stayed on.