250 was probably an overshot. I know some bass players that can play somewhere around 220-240 bpm. One was on a youtube video showcasing a practice technique. Idk what it was called though. I know Billy Sheehan could at least play triplets at these high speeds.
Yes, Billy has a very POWERFUL right hand.
"La Incredible" Billy
Billy Sheehan - Bass Solo
Here is his Intro lesson.
