Your a 100m guy aren't you? (still
)
One of the biggest issues I have with defining a "zero" is you need to know the trajectory of your bullet from 0--> 2x times past where you think your going to shoot, regardless of where you zero your POI/POA to. This is exceptionally important for CONUS LE - where I have seen some massive misunderstandings of bullet trajectory (most came from Big Army)
Additionally what your expected engagement ranges are (as this can play a large factor).
Roland will (or at least used to) zero at 100 - but he'd damn well know his zero (and confirm and confirm and confirm) from smash in the grape out to it's really hard to see.
If your like me, and on a budget - I simply grab a few data points
1) have Magneto Speed, and AB app
2) zero gun (and get MV's with the Magneto) shoot 4 x 5rd groups or better yet more (better MV data - and better knowledge of what group is)
3) confirm ballistics chart with live fire on a few ranges (close, medium, far - these ranges will be platform specific as truing a 10" gun at 700 is a little dumb)