While up on the mountain this week I decided to shoot a rock at 1540 and was hoping for a first round hit. Nope high. Like 1 moa high. After several shots and misses I adjusted my speed and bingo. I ranged a new target at 1300 and bingo dead on. So the speed I have been using has been working at lower elevations seemingly fine. Meaning I have hit most targets with decent accuracy. Do you guys ever have to readjust speed or just use the computer? I am confused for sure. I am using shooter and needed to add 30 fps to the speed. I shot another 4 or 5 and they were good on elevation.