Originally Posted by Shawn Carlock
Two things to look at:
1. Even though you are shooting level are there any ridges, slopes or draws between you and the target? If there are with a head wind these terrain features can cause a lift and make you shoot "flatter". If not then look at # 2.
2. Take your Kestrel out and page to BAR Pressure, on most modles hold both buttons down and it will switch to a screen with elevation this is the elevation the pressure is referenced to, make sure it is at "0". Now your Kestrel thinks it is at sea level no matter what and gives you "raw" or station pressure. Enter this into your Kestrel in the pressure at altitude box and uncheck "calc std pressure" box. This should enter the correct pressure into Exbal.
Also just in case check the basics:
Check 100 yard zero.
Check that click values are .25 moa.
Check every single box in Exbal to ensure all data is correct.
Hope this helps.
Yes I am shooting accross a draw that drops around 200 ft then rise to the target at about the same height as I shoot from. The heads of the trees in the draw I shoot accross are at around the 750 m mark. The breeze was good and steady hitting me on the nose straight on.
I checked the kestrel and pressed the sequence of buttons and it showed zero with a blinking (ref ) , I quess that stands for reference. Tonite I get sittng at home 29.77 inHg ? My alt at my house is 140 ft currently.
I checked the conditions from the previous shoot. I was firing from a different position at the same gong, but the distance was 700M. Guess what ? The wind was also solid 4-5 mph from 12 oclock. The shot travels over the same draw. Exbal came back with 16. 5 moa up. I ended up shooting 14 moa up in real bad mirage and landed the 3 shot cluster about 4 " dead centre high of the black circle. This really suggests that the shots travelling over the draw in a head wind most likely are getting around 2 moa lift ? Does that seem logical ?
I also had a 415 gong out that day and shot across the same draw. exbal gave 7.5 up in the mirage. I ended up shooting 6.5 up and still was 10.5 " high of centre. Maybe a combination of mirage and lift ?
The same day I fired at a 340 m target that is .99 cosine down hill with no draw to cross. Hit dead centre ?
Maybe I should try and set up a long flat shot at 1000 and take the draw out of the equation to see if the pda agrees with the strikes. I would have thought that should conclusively tell me if the draw I'm firing across is causing the lift ?
What figure do you use in the scope height above bore. I put in 1.5 " ?? BC is .768
It sure makes you strut around a little when you hit your first 1000 + target in the lungs.