A while back, my brother sent me some ballistic information for a .50 BMG. I went to the website, input the bullet information and it told me where the bullet should hit at defined ranges based on a 500 yard zero. All seemed right with the world.
When i was in Louisiana, we sighted the rifle at 25 yards. According to the charts, i should sight it 4" high at 25 yards and it should be dead on at 500 yards. We played around and got the windage perfect and then set the elevation. All seemed right with the world.
When i came back home to West Texas, a buddy of mine and myself went to his farm and stretched out 500 yards and set up a sheet of plywood as a target. First shot, nowhere on the target. Second shot, nowhere on the target. Something seemed amiss.
I moved up to the 200 yard mark and couldn't hit the target. I moved up to the 100 yard mark and the bullet was about 5 feet high. Just a wee bit off of what the ballistic calculator said it should be.
I zeroed it at 10" high at 100 yards and then moved back to the 500 yard range. The bullet was now on the target. Finally, $25 later no doubt. The wind picked up bad so we had to stop the shooting. I plan on going out to the range when the wind isn't blowing and zero it in tight at 500 yards. We were just fooling around and hit a 1" thick steel plate at 300 yards and put a hole in it with a FMJ. Very impressive.