AB Data not lining up

[rangeryo]

Okay okay, I'm sure it's out there, and I'm sure I could find it if I dug hard enough with the search button, but I'm a busy guy, and I'm hoping someone can give me the skinny on my applied ballistics data.

I'm shooting a 308, 175 SMK's. Checked with a labradar and a standard optical chrono consistently reading around 2720 fps. Input the velocity, correct scope height, environmental factors, elevation and AB's bullet library data for the 175 SMK, I can not for the life of me get my data to line up. I've been forced to run ballistic calibration based on known impacts and AB has adjusted my velocity all the way down to 2640. What could I be missing here?

 

[Mordamer]

Okay okay, I'm sure it's out there, and I'm sure I could find it if I dug hard enough with the search button, but I'm a busy guy, and I'm hoping someone can give me the skinny on my applied ballistics data.

I'm shooting a 308, 175 SMK's. Checked with a labradar and a standard optical chrono consistently reading around 2720 fps. Input the velocity, correct scope height, environmental factors, elevation and AB's bullet library data for the 175 SMK, I can not for the life of me get my data to line up. I've been forced to run ballistic calibration based on known impacts and AB has adjusted my velocity all the way down to 2640. What could I be missing here?

One possible reason is that your scope is not tracking correctly.

 

[ShtrRdy]

What distance are you shooting? Have you confirmed the distance with a LRF?

 

[Lowlight]

The best way to figure this is to post

1`. All your verified drop data
2. Conditions you shot under
3. we have your MV, but a screen shot or repeating your inputs would be helpful

 

[JMGlasgow]

Have you input your zero offset? Are you using banded bc's?

 

[rangeryo]

One possible reason is that your scope is not tracking correctly.

Kahles 625, I sure hope this isnt the case.

 

[rangeryo]

What distance are you shooting? Have you confirmed the distance with a LRF?

Shooting matches, targets out to 1100+ yards

 

[rangeryo]

The best way to figure this is to post

1`. All your verified drop data
2. Conditions you shot under
3. we have your MV, but a screen shot or repeating your inputs would be helpful

I think I realized where a big part of my problem lies. When I got my kestrel, I didnt know anything about reference altitude/baro pressure settings. I was using station pressure, and altitude for my environmental variables. I'm wondering if maybe I should have just been ticking the "pressure is absolute" box in the AB program.

I tried last night using the reference altitude/baro adjustments, and then set baro back to station pressure and noticed my elevation went from 315 feet to 8 feet. Still new to the kestrel (using 3500) so I'm not sure If I did more harm than good figuring that stuff out.