I made my zero be 200 yards. Then I made a target on white cardboard that was 30 inches wide by 48 inches high. I put my 100 yd. target at the top. Then I shot my group at 200 yards. then I moved back to 300 yds. and while aiming at my 200 yd. zero I shot a 5 shot group. then I moved back to 400 yds. and shot another 5 shot group while aiming at the 200 yd. zero.
Then I measured from the center of the 200 yd. group down to the "CENTER" of the 300 yd. group and down to the "CENTER" of the 400 yd. group.
This gives you the arc that your bullet takes going down range. I gave this to Paul at Vortex plus the elevation, humidity and elevation. He then made his computer program numbers match the arc for the elevation I was going to hunt at.
It worked perfectly. Read below:
Testing new Vortex custom turret. - Georgia Outdoor News Forum
When I got to Wyoming where it was 4500' elevation The custom turret was dead nuts accurate at all the 100 yard intervals out to 900 yards.
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