Re: Corrected FPS?
In theory, the answer would be yes. By zeroing at 100 yds and then shooting a second group at 600, you would learn/confirm the number of MOA or Mils (whichever you are using) necessary for dialing up. By inputting your bullet BC and other external conditions into some ballistic software, you could back into an estimated muzzle velocity through trial and error.
In reality, the answer isn't always that simple. There are so many variables that go into calculating a "ballistic blueprint" of what your bullet is actually doing in its flight. For example, some bullet mfgs overstate the BC of their bullet. Your software has no way of knowing this. It simply takes for granted that the BC input by you is accurate. So when you begin to "play" with various muzzle velocities to arrive at the correct MOA dial up, your velocity will be artificially low. The truth could very well be that your bullet is traveling faster than your assumed muzzle velocity and the faulty BC number is the culprit instead.
The same goes for elevation, temp, G1 BC vs. the more accurate G7 BC, etc. Your software assumes that all these measurements are correct. It's always better to confirm all your data and then tweak or message the software. One final caution, not all Chrony's are accurate either. :-)