Don't forget to correct for magnetic declination or your numbers will be wrong. Magnetic declination changes based on where you are on the planet. Coriolis adjustments of useful accuracy require that you account for the fact that true north and magnetic north are different but people tend to get their heading with a compass which is giving the user magnetic north.
There's no such thing as a half or quarter value for it (coriolis adjustment) unless you're academically multiplying by .5 or .25 because that's not how angular systems work. If you were to do it the old way shown in military field manuals then you'll be doing it wrong. Doing it wrong will have less of a useful effect than not doing it at all.
<rant> As a sort of side note: The military field manuals do the whole full/half/quarter value nonsense because it's close enough to put bullets at heads-down effect close and it's easier for people with 2 digit IQ's to understand than angle cosines, not because it's "correct". The technically correct way of adjusting for things like that is with angle cosine multipliers. </rant>)
Assuming a magnetic declination of 0deg for simplicity, a 45deg shot angle offset from true east or west produces a cosine of ~.7, not .5. So, if you were to have an indicated full value correction of .1mil for true west then the adjustment for north west (45deg north of true west) would be .07, not .05 as one might think. If you're anywhere near the Mississippi river then it doesn't matter much but as you get near the coasts it starts to matter a great deal as far as the whole thing goes.
Which brings me to my 2nd point: You're getting into the weeds by even bothering with vertical coriolis at such near distances. 3" at 1000yrds is very roughly .1mil which is smaller than the normal average group size from a highly skilled shooter with a highly tuned rifle and it's inside the vertical dispersion that a normal shot-to-shot velocity dispersion would generate. Meaning, you're trying to dial for something that's basically noise. Don't waste the effort. Bothering with it inside of a mile just makes the maths intensely and ridiculously more complicated than it needs to be.
