Been trying to get a grasp on this Density Altitude thing.
A friend at work just got his pilot license. He flies small Cesna type airplanes out of North Omaha. As a pilot, he has firsthand knowledge of DA. He told me that as of this AM at 11:00, the DA at Blair airport was just short of 4000'. This is from a set altitude of close to 1300'.
Now I took this info and went to Federal Ballistics website and entered for 175 SMK 308cal. 1st entry at 1300' and temp of 70. 2nd entry at 3500 ' and temp of 70. Both with 200yd zero.
The trajectory diff was only 1.3" at 500yds, 2.8" at 600yds, 4.9" at 700yds, up to 19.3" at 1000 yds.
I found this incredible, as I had no idea that around here (Omaha area) that we could have such a huge swing in altitude which affects ballistics by a huge amount when trying to engage a 24" target.
Just an FYI and hope I am correct.