I am relatively new to long range. Yesterday I went to the 1000 yard/mile range for the forth time in the last few months and am noticing a trend that I can't figure out. Multiple ballistic calculators give the same data. Load is chronographed per temperature, single digit SD. Data seems good out to 6-700 yards. At 1000 I have to at .5 to .75 MOA elevation and hold .5 left with no wind. At one mile I'm adding about 6 MOA elevation and almost 4 MOA left again with no wind. Shooting direction is East. Is the added elevation due to BC lowering with loss of speed? Is drift due to spindrift or rotation of Earth. Any help is appreciated.