Driving your ballistic app

So how do you guys use your app? More for extended ranges. I'm using Shooter.

Its taken me ages to work a few things out as I went with help from guys on here.

I have a couply questions still.

I set my pressure to absolute so I don't have to enter altitude.
How important is humidity? Can get temp but humidity I cant get unless in cell range and that's from station where ever that is.
Do you guys set your zero atmosphere data for each load and enable that? What effect does this have and what does it use if you don't enable zero data?
At what distance do you begin to bother with Coriolis?

What other tricks or things I should know about?

Regarding humidity.. here's a nice experiment to see for yourself.

Set up your solution for a long way off, as far or further than you'll ever likely shoot on game.

1. Set humidity to 0% - Note drop.

2. Set humidity to 100% - Note difference in drop.

3. Set humidity to 50% and leave it there forever.

I just use 50-70% humidity as we don't have issues with it generally in NZ. Doesn't have much effect anyway if you're not shooting bullseyes.
Always use station pressure off my kestrel or watch as it has proved accurate in the field.
Get them and your angles right and your good to go.


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Sweet as, my garmin 650 does pressure so will use that.

I leave humidity at 50%. I don't worry about coriolis, but the furthest I've shot at game is 600 yds. Past 500 yds it will start to make a difference.

I tend to find a glassing point and sit and wait. When I get there the first thing I do is set the pressure and temperature, select the rifle I am using etc. Then when I see an animal the only thing I need to do is set the range and angle.

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Originally Posted by Gibo

So how do you guys use your app? More for extended ranges. I'm using Shooter.

Its taken me ages to work a few things out as I went with help from guys on here.

I have a couply questions still.

I set my pressure to absolute so I don't have to enter altitude.
How important is humidity? Can get temp but humidity I cant get unless in cell range and that's from station where ever that is.
Do you guys set your zero atmosphere data for each load and enable that? What effect does this have and what does it use if you don't enable zero data?
At what distance do you begin to bother with Coriolis?

What other tricks or things I should know about?

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if your phone is capable ( mine is galaxy S4) then it is able to read humidity, temperature and altitude from the sensor, so just put in that data from the phone, rather than relying on an internet weather station that's no real relevant location to where you are

set my zero atmosphere data when I zero the rifle, so say the range is 100m above sea level and humidity is 60%, temp is 17 degrees and pressure is say 1010hPa that day, then that be comes your zero data

600 plus all these things wil take effect, angle is most brutual if you don't get it right

Zero atmosphere only becomes important if your zero is a fair way out.
Zero at 100y or m atmosphere is pretty negligable.

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Sweet as. Yeah i make sure my zero is spot on. My rangy does angle so no issues there.

By a fair way out I ment if your zero was at say 400y for whatever reason then a change in atmospheric could change your zero and shooter will account for that if zero atmosphere is enabled.
But if your zero is at 100y any change in pressure you are likely to experience is going to have very little real effect on your true zero as it has so little atmosphere to travel threw on its way to 100y.
So zero atmosphere not required if zeroed at close range ie 100y

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Originally Posted by veitnamcam

By a fair way out I ment if your zero was at say 400y for whatever reason then a change in atmospheric could change your zero and shooter will account for that if zero atmosphere is enabled.
But if your zero is at 100y any change in pressure you are likely to experience is going to have very little real effect on your true zero as it has so little atmosphere to travel threw on its way to 100y.
So zero atmosphere not required if zeroed at close range ie 100y

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Ah that makes sense. Cheers man. I will disable it so its one less thing to think about. I do zero at 100.

Your phone will have one flaw - the temperature is always reading about 26deg....about the same as a running lithium ion battery. It can be tweeked with a third party app but then the corrected temp can't be fed into 'Applied Ballistics'. I had shooter but I found AB to be easier to customise.

Could buy a suunto watch, will give you pressure and temp if you take it off your wrist

One thing I've always wondered about the app inside the kestrel - can it have the clicks true'd up like you can with AB? I have to do that because my clicks on a march are not to the same std as AB. Can the custom function just enter real world POI data?

I had the s4 samsung and it would give very close readings to my kestrel.
this is the only phoneI know of to have the 3 sensors.
my s5 samsung does have pressure but I do miss the temp.
humidity doesn't matter till ya long ways out.
I have used the balistic watch which is great if ya have the one rifle.
next purchase might be the latest kestrel that litz and hodnett have been working on.
my mate scored one and reckon they are the ducks nuts!
the 2500 kestrel does all you need until ya get past how far the 338 goes.
also fuck shooter ap as it has glitches that he won't fix.
AB is more expensive but you get all litz's real world bc data and latest projectiles updated and always improving it as well.
I like his truing function to as they are also working out the magnus effect which happens further out than I can see!
keep your app on simple and don't think about coriolis til you've mastered to 1000 and even then wind and spin drift will fuck ya up before the spin of the world will!

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If you're on pressure is absolute isnt temp irrelevant?

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Nope, pressure is absolute gets rid of altitude effects.

still need temp.
density altitude is the 3 in one

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Except for gravitational attraction which is inversely proportional to distance 😀

Interesting just tried it and yep makes a difference. I have always just guessed temp.
I was incorrectly thinking that if colder air is denser then it would be accounted for in pressure which is a measure of air density.

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V C is correct. Temp can affect pressure but only if the gas is not free to expand like inside a pressure cooker.

PV = nRT

P pressure
V volume
n number of "air molecules"
R = a conversion constant
T temp above absolute zero

The real atmosphere is free to expand so V changes.

At a given pressure (say 850 mbar is typical at 1500m ASL), if the temperature is higher then that pressure can be maintained with fewer air molecules per volume. Its the air molecules which slow your bullet down.


It seems that air pressure doesnt fall off in a simple way wih altitude. So there is a "standard atmosphere" ICAO model which is used to reference the "density altitude". If someone could tell me where to find a table for that, covering hunting altitudes (say up to 4000m) that would be interesting.

Buggered if I can remember off the top of my head but working out density altitude from known variables was an easy formula.

I would have to go back thru my metrology books from flight training.

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Originally Posted by R93

Buggered if I can remember off the top of my head but working out density altitude from known variables was an easy formula.

I would have to go back thru my metrology books from flight training.

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the flash kestrels do that for ya r93!
saves burning up those brain cells that are fast dissapearing

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Dunno if my one does. But it gives me accurate enough readings to shoot as far as I am prepared to.

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mine is the 2500 and does pressure and temp which effectively is all ya need

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Quote:

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Originally Posted by R93

Buggered if I can remember off the top of my head but working out density altitude from known variables was an easy formula.

I would have to go back thru my metrology books from flight training.

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https://wahiduddin.net/calc/calc_da.htm
I used to use this until I noticed how much DA changed though out the day. Sorting out my s4 was as far as I got to having accurate DA in the field but you still must know your real alt and your phone can't be warm from your pocket.

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Originally Posted by Dead is better

https://wahiduddin.net/calc/calc_da.htm
I used to use this until I noticed how much DA changed though out the day. Sorting out my s4 was as far as I got to having accurate DA in the field but you still must know your real alt and your phone can't be warm from your pocket.

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your right about making sure your phone not been warm.
I have checked against my kestrel and the 3 values are very close to what the kestrel tells me as in it doesn't change the app result in adjustment.

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Warm phone, same goes for my watch

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Originally Posted by andyanimal31

mine is the 2500 and does pressure and temp which effectively is all ya need

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Same. It seems to be very accurate.

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speaking of warm, I found carrying the ammo in my top pocket has kept my ES on 7mmremmag down and lifted the FPS.