I don't know the fps, but i can say the 30-06 with the saboted 55gr bullet zings em out there!
Remington Accelerator, i think the cartridge was called.
Those were just over 4000 FPS. A quick look in my Hornady book the fastest published load I see is for the 223 WSSM, pushing a 40 gr VMAX at 4600 FPS.
Next is the .220 Swift 35gr NTX up to 4500 FPS.