Can firmware hacks change the shortcomings of the D600 or is it crippled by hardware?

If you want to shoot bullets, then you need your camera on B and not 1/4000 or 1/8000,

You use either an IR beam or a sound activated strobe with a timer delay, and stop the motion using the flash,

when the sound is detected, the flash is activated, all you need to do is to dial in the delay between the sound being herd and the flash being fired,

If you are tying to stop a bullet at 1/4000 by hand.....
Im not saying you cant do it that way but if you fancy a challenge  then the best of British .

Mac.