Calling Hornady 4DOF App expert's - issue with Altitude and Pressure relation

[Arvad]

I have an issue when setting the "Zero Angle" in the 4 DOF App, more specifically to the relationship between "Altitude" and "Pressure".
This weekend I was at a range planning to re-zero my rifles using "Zero-angle" but ran in to some problems as the app kept saying there was an "Error" when trying to calculate the "Zero Angle".

I suspect the issue I'm having is related to the before mentioned relationship between "Altitude" and "Pressure.
On Sunday the "Pressure" was 1026mb at 3m above sea level - the pressure was measured using my Kestrel (5500), and i was getting the "Altitude" from my phone using a GPS app to give me this. The range is literally at the edge of the sea, and we are shooting out over the water, so the 3 meters above sea level can't be completely off.

The pressure I'm using from the Kestrel is the "Station Pressure" not "Baro"

If I enter the "Altitude" value in the app first, it auto corrects the "Pressure" value to 1012.95 mb, and then it lets me calculate the "Zero Angle" but I would now be running with the wrong "Pressure" value, which would be counterproductive and wrong as I'm aspiring towards ELR shooting, where I need to make sure I have all parameters under control.

The same thing happens if I enter my enviromentals on the 4DOF HUD - if the "Altitude" and "Pressure" isn't within the range the app finds to be matching, it won't calculate a firing solution for me, and just set both elvation and windage to zero no matter the distance or wind.

I have been watching all the Horndy videos on youtube over and over trying to find the detail I missed, but can't figure out what's wrong.

Has anyone experienced the same issue and found a solution?

 

[_Windrider_]

Are you zeroing at 100m or some other distance?

 

[Arvad]

The distance was at 100 meters, verified with laser.

 

[_Windrider_]

I wouldn’t worry about zero angle for a 100 meter zero. If you verified it with an LRF it’s inconsequential. It would be more important to record any offset from POI and POA to get your true range zero.

 

[lumberjack78]

Have your pressure come in from your Kestrel and don't worry about altitude.

 

[Arvad]

I have been testing this evening, and it just seems there is a bug in the 4 DOF basically making the pressure component unusable. I can't just connect my Kestrel as this in it self seems buggy as hell and pulls in strange numbers most likely because it get confused over the pressure and altitude. The issue seems to be specifically related to days with high pressure. Out to 1000 meters the issue don't seem to bad comparing to Applied Ballistics, but at 1600 meters + it starts becoming an issue not being able to correctly account for the correct pressure. So I'm starting to think 4 DOF might just be a waste of time for ELR. Really a shame as the UI is way better than AB's

 

[_Windrider_]

I have been testing this evening, and it just seems there is a bug in the 4 DOF basically making the pressure component unusable. I can't just connect my Kestrel as this in it self seems buggy as hell and pulls in strange numbers most likely because it get confused over the pressure and altitude. The issue seems to be specifically related to days with high pressure. Out to 1000 meters the issue don't seem to bad comparing to Applied Ballistics, but at 1600 meters + it starts becoming an issue not being able to correctly account for the correct pressure. So I'm starting to think 4 DOF might just be a waste of time for ELR. Really a shame as the UI is way better than AB's

That pressure setting is only in the zero angle determination. the kestrel should update normally otherwise. I know you are in EU or something, but try using in Hg instead of mb. Maybe the bug is the units. Just a thought

 

[_Windrider_]

Post your gun build and setup. I’ll try and duplicate.

 

[Arvad]

The most of the data is in the screen shot of the zero angle page - it's a Ruger Precision in 338LM using the 300gn Lapua Scenars.

I just tried to change the pressure units, and it's still the same issue.

I'm in Denmark BTW

 

[_Windrider_]

The most of the data is in the screen shot of the zero angle page - it's a Ruger Precision in 338LM using the 300gn Lapua Scenars.

I just tried to change the pressure units, and it's still the same issue.

I'm in Denmark BTW

But give me your gun. Sight height. Twist. Etc etc. I have to replicate that before I can do anything

 

[Taylorbok]

But give me your gun. Sight height. Twist. Etc etc. I have to replicate that before I can do anything

it's all in the screen shot. only thing missing is MV. I used 837 M/S. It works for me when I enter everything manually. However, I had to convert Mbar to inHG. My App stays inHG even when in metric. Can you change the pressure unit in the kestrel to inHG and try again.
I'd bet that's where the glitch is. If it's trying to use 1026 inHG it's gonna have a spaz

 

[Arvad]

Morning guys.

The rifle is new so I'm running a MV at 780 m/s.

Just tried to change to inHg - still the same issue. It just doesn't want to calculate in high pressure.

Rifle data:
MV 780 m/s
Sight height : 7.1cm
Twist : 238mm (1:9.375")

What I just tested
Pressure: 30.27 (pressure this morning)
Height: 3m

Tried it both in the zero angle dialog and HUD. Zero Angle gives error, and HUD don't want to calculate.

 

[isofahunter]

How are you getting , instead of . In sight height and pressure? While my 4dof shows , on key board does not allow input?

 

[Taylorbok]

It seems to work fine for me. However this morning when I go into it half the inputs are metric and half are imperial so I don’t know wtf is going on there

 

[Arvad]

Ok, finally got a chance to do some testing again. I copied my gun profile and changed everything in to (US) units, and it seems to be working.
So the conclusion must be that there is a bug in the conversion when using metric units in 4 DOF - seriously annoying. So now I need to decide I want to convert everything in to US units for everything I do.. Or start using AB.

 

[Taylorbok]

Message Hornady about the issue. I’m sure they can rectify it. I’d like to see them go back to using regular zero. Fuck that zero angle BS. I know you can but then it doesn’t allow you to use a zero offset.

AB has a bunk user interface and is missing some nice features and usability of 4DOF but I’m sure it works

 

[pell1203]

I called Hornady because I was also having pressure issues and the solution was not changing when the absolute pressure was manually changed from 985 to 885 mbar (or hPa) and was told there is a bug they are working on with regard to metric units. After changing units to imperial values the app responded to manually updated pressure changes a couple of times to but then got stuck again. Basically untrustworthy/unusable if using metric values.

Best thing to do is call Hornady and let them know. The more bug reports come in the higher the priority they will assign to getting it fixed.

 

[Rockhurr]

Ok, finally got a chance to do some testing again. I copied my gun profile and changed everything in to (US) units, and it seems to be working.
So the conclusion must be that there is a bug in the conversion when using metric units in 4 DOF - seriously annoying. So now I need to decide I want to convert everything in to US units for everything I do.. Or start using AB.

Used 4DOF for 6 years now, never had problem with Imperial units.