Hornady 4DOF bug found with Altitude input

[iceng]

Was out verifying data today. Density Altitude on my Kestrel 5700 elite was -190m. Mates was also reading the same on a 5700. We are in Australia and it's winter, morning, and this it normal.

4DOF will NOT spit out a solution in negative altitude. I can reproduce the error. Shooting buddy's phone does not have a problem. He gets a solution.

I tried uninstalling / reinstalling from app store, no difference. I did have to enter all my rifle data again.

Hornady 7mm 162gr eld-M.

Me: Android Oppo R17 Pro
Him: android Sony Google pixel

My kestrel: 5700 elite, latest firmware.

Yes, my 1mile (1609m) DOPE is verified, I hit the target. I'm sure someone was going to ask.

Was doing some testing for a project, had 404m, 720m, 1015m and 1609m.

Can anyone reproduce the error where their data will NOT compute in negative altitude ?

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EDIT
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I've been playing and trying to reproduce numbers. I've found that altitude and pressure are linked and move "together". I can't manually enter pressure. If I enter an altitude, it slides accordingly. So I set it to 1m altitude, and it's 29.92inhg. (auto generating and using this result)

If I set to -100m altitude, I get 30.28inhg, which is basically correct, but still get no output. Altitude must be a positive number (for me).

 

[Shootin Stuff]

I just had a play with mine. It’s giving a solution for below seal level in both BC and 4DOF mode. I am manually entering data at the moment, but I have to enter elevation first and then pressure, changing elevation would alter pressure.

Are you paired to a weather meter? Mine would not give a solution when connected to my weatherflow so I enter manually for the moment until I hear of a fix.

 

[iceng]

Not currently paired, entering data manually. I can pair and test. Might be good to try. However shooting location is different to my nice warm house.

 

[JMGlasgow]

What is the average winter temperature in Australia?

Off topic but I'm curious

 

[b2lee]

404 - Altitude Not Found.....heh

With the coming war of light vs dark....we need negative altitude DOPE so we can fight on their turf!

On a more serious note....which bullet you using for 1 mile?

 

[iceng]

Weather in Australia. I'd never seen snow until 18 months ago when I was in USA. However I feel that our cold is just that, it goes straight to your bones. Cold.
http://www.bom.gov.au/sa/forecasts/adelaide.shtml. Weather is nice today.

I was shooting the 7mm 162 eld-m @ 1mile.

 

[JMGlasgow]

The weather forecast you posted would have me in a short sleeve shirt.

 

[Shootin Stuff]

Maybe someone who knows can chime in, but I’m not entirely sure why 4dof even needs evelation AND barometric pressure, because barometric pressure is the pressure altitude. Apply the temperature correction and you get density altitude.

The way that making an elevation adjustment messes with pressure makes me think it uses standard pressure at that elevation as a baseline and applies a correction of the difference between std and actual pressure rather that calculating directly from real time barometric pressure.

I will need to have more of a play with it, but it would be nice to know what entering the actual elevation changes the calculation.

 

[lumberjack78]

Maybe someone who knows can chime in, but I’m not entirely sure why 4dof even needs evelation AND barometric pressure, because barometric pressure is the pressure altitude. Apply the temperature correction and you get density altitude.

The way that making an elevation adjustment messes with pressure makes me think it uses standard pressure at that elevation as a baseline and applies a correction of the difference between std and actual pressure rather that calculating directly from real time barometric pressure.

I will need to have more of a play with it, but it would be nice to know what entering the actual elevation changes the calculation.

Altitude is likely in there for the folks that don't have a Kestrel, but do have a watch or something that gives them a decent altitude. Then they can just adjust that, the pressure changes for them, and within 800 yards or so, they can be pretty accurate.

 

[Shootin Stuff]

Altitude is likely in there for the folks that don't have a Kestrel, but do have a watch or something that gives them a decent altitude. Then they can just adjust that, the pressure changes for them, and within 800 yards or so, they can be pretty accurate.

This was kind of my thinking as well. Enter an elevation if that’s all you have and it will likely spit out a number that’s close enough, but enter barometric pressure and it will make an accurate correction based on that.

 

[iceng]

I'm possibly heading back out there again soon, maybe a week or 2. I'll hopefully take some more data and even a video of the results. Plus shooting, coz that's always good.

Thanks for people's help. Strelok was my go-to, and it spat out valid data. I wanted to verify 4dof because i was using Hornady bullets.

Still can't beat pen and paper..