I'm doing an 90 degree attack (90 degree AOB), so range shouldn't matter and AOB error should be slight. I was shooting from about 1500m.
Only thing I can figure is I did not record time correctly with the stopwatch. I can't make out any minute marks on it so it is difficult to figure our when 3 minutes expires. I did it just by keeping track in my head how many times the second hand passed 12 o'clock. Maybe I lost track.
Steve