Real world trajectory data

"fishinwrench"
I guess I never indicated that I was running chairgun on my phone (mobile app)
Well, at my daughter's request I deleted and reinstalled the app. Guess what?
<ducking and covering head> 
Really sorry! And thanks so much for all the help. I truly was about to pull my hair out.
It never occurred to me that the app was not performing right. Good grief!
Look at the positives - the topic comes around every so often and new folk, and others, get to see a balanced picture and whatever support folks have to offer from their experiences.
Chairgun does work - there are limits particularly if using generic bc values not derived for the particular rifle and pellet combination.

If you have the time at the shooting location and I might add, time of day, three groups shot at different ranges and massaged in a best fit polynomial will give precise results.
Otherwise one is pretty much stuck with the long haul of shooting every relevant range and constructing a drop chart from the results. But one must factor in some elevation errors if the chart is shot early in the morning or late in the day or at night when the air is still (good) but the temperature is way off what it may be on the range in the middle of the day during competition. That is one reason that in benchrest matches shooters are all allowed sighters in their relay at the side of their card. It could be some hours between the sighting in period or day, and being called to the line. Same applies in hunting. Expect a lower POI early and late in the day especially at longer ranges. An inch and more at 100 yd is not unusual between 7:00 am and 11:00 am at my farm. ....
Best wishes in all your shooting endeavours, regards, Harry.