I'm going to try taking a 5.56 AR out to 1200 yards with 80gr SMK's this weekend and have a recently purchased Strelok Pro app to put to the test.

Strelok gives me the option of turning on or off spin drift and Coriolis factoring.

When I turn it on it's showing me as needing to add a left windage adjustment culminating in 1.7 MOA at 1200 yards.

Any learned opinions on whether I can expect that to be accurate or how it's determining that info (why left instead of right)?

The target is a 24" circle gong (2 MOA at 1200 yards) so the adjustment is plenty to make me miss the target if it's wrong.  I've never shot that far and won't need any help missing the target.  

KS is in the northern hemisphere, correct?

Because the horizontal component of Coriolis in the northern hemisphere requires a left correction.

At that range you will also have to compensate for the vertical component of Coriolis (aka Eotvos) effect.

The bullet will spin drift to the right(right twist) so you have to compensate left.


Coriolis will depend on azimuth and latitude.


Considering your flight time, most certainly use spin drift and might as well turn on Coriolis as well. Bring your compass.

Man this is way out of my league!  LOL

The good news is the forecast is looking like a tailwind most of the day!

ETA - The other good news is I'll get 5 shots before I'm done so hopefully I can call some good shots.

You don't need to worry about any of that shit. Just put in your azimuth( compass heading in degrees for direction of fire) and latitude at your location Strelok will take care of the rest.

I was hoping it would.  Thanks!