Re: Dave King or JBM, Help! I found a ballistics problem!
I don't have my Exbal PDA program right in front of me but, there's a check box somewhere in there that says "use field data". If this box is checked it will assume you've rezeroed at your current field conditions, and this would be closer to being zeroed at 300 yards than if it were using your original sight in conditions at lower altitude with the box unchecked.
I'll have to play with it a bit and see how mine's working.
I know you should see a remarkable change throught the trajectory curve if zeroed at sea level, use those sight in conditions then jump to 10,000' ASL.
POI may well be .5 MOA higher, so 2.25-2.50 MOA at 300 yards would now be more like it for a 300 yard zero.
The program should know what the total POI deviation from LOS would now be at whatever range. It knows the zero range, the atmospheric conditions at sight in and now in the field conditions and should modify the curve and resultant MOA correction at any range.
I wonder if the MOA correction Exbal gives on the calculate page matches the MOA correction in the drop chart page? Been a while now since I played with the program. Got to go locate my PDA come to think of it....