Sig Kilo 2400 variance from AB app

[slim9300]

This is just kind of a FYI thread after dealing with Sig CS (not helpful) and troubleshooting the device. I have had my Kilo 2400 for about 8 months and the first time I set it up, it matched my AB app nearly perfectly when tested in the field.

Two weeks back I started comparing my AB app dope and my info from the rangefinder while measuring BP, temp and humidity. I had a problem. They didn’t match and they weren’t very close.

I attached my bullet info via images of both the Sig app and AB apps. Both profiles use the custom BC for my 210 Nosler ABLR bullet. In AB’s iPhone app I have my 100 yard zero 0.5” high. In the Sig Kilo 2400 app, per Sig this has to be a negative number to match. For the longest time they were both matching with the Sig at -0.5” zero height.

Today I went back and forth making a small tweak to zero height until I finally got AB and the Sig app to be nearly a perfect match. What’s odd is that it took a zero height of -1.2”.

Considering it’s damn near perfect now I doubt I’m going to change anything, but does anyone have the same experience? I have read about people having a significant variances from their Kestrel devices and AB software (likely due to temp and BP differences).

At the following BP (29.51), temp (59.0) and humidity (66%) this is what I got.

Range 523 yards - AB app: 6.6 MOA - Sig Kilo w/ -1.2” zero height: 6.61 - Sig Kilo w/ -0.9 zero height: 6.89

Range 682 yards - AB app: 10.5 MOA - Sig Kilo: 10.63 - Sig Kilo w/ -0.9 zero height: 10.95

Range 814 yards - AB app: 14.4 MOA - Sig Kilo: 14.43 - Sig Kilo w/ -0.9” zero height: 14.68

Range 1050 yards - AB app: 22.3 MOA - Sig Kilo: 22.28

Range 1390 yards - AB app: 37.0 MOA - Sig Kilo: 37.02


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[J8tnub]

Do you have a wind value plugged into your Kilo App?

 

[J8tnub]

Any HUD screen pictures?

 

[doverpack12]

Does the sig allow you to input zero atmosphere to match the applied ballistic app?

 

[slim9300]

Do you have a wind value plugged into your Kilo App?

I made sure it matched both apps. 10 mph at 9pm.


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[slim9300]

Any HUD screen pictures?

No but next time I’m going to take those for comparison.


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[slim9300]

Does the sig allow you to input zero atmosphere to match the applied ballistic app?

That would be very helpful if it did. I don’t believe it does. Also if there was an ability to run the data without actually ranging targets through the app I would be much happier.


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[wind gypsy]

I assume site height is the same for both? The AB app doesn't show it on your screenshot.

 

[J8tnub]

Do you have spin drift and Coriolis enabled on the AB app? It’s always on in the kilo. As well as Aerodynamic jump. You could try taking the wind values out and see if they match.

Did you also make sure to set the Kilo latitude to your actual latitude?

 

[HellsCanyon]

I would disable your zero atmosphere in the AB app. That's really only needed if you're zeroing farther than 100 yards which is why we run 100 yard zeros in the first place. Curious to see if that changes anything.

I'm going to run some simulations out my shop door this afternoon and see what kind of info I can get with the kilo vs. my tried/true Shooter app.

Mike

 

[Mtslackcountry]

Do you have spin drift and Coriolis enabled on the AB app? It’s always on in the kilo. As well as Aerodynamic jump. You could try taking the wind values out and see if they match.

Did you also make sure to set the Kilo latitude to your actual latitude?

How do you set your latitude?

 

[J8tnub]

Target screen. Can be found on the main app screen

 

[HellsCanyon]

Alright I went and ran some numbers this evening. Here's what I've found...

First, one tip:
You can override environmental inputs in the app by going to the environmental display, and tapping the orange kilo sign next to temp, pressure, humidity. You can also change wind speed and angle from here. Once you change something, you have to sync it to the rangefinder.

I also noticed my rangefinder kept bouncing back and forth between 59* and 71* between the HUD and Environmental screens. Want to check into that more, but I overrode it to 59* for the sake of testing.

I ran three different profiles in the Sig 2400. All identical except for BC "types".
Profile CD = Custom Drag Curve profile
Profile G7 = G7 BC value used
Profile G1 = G1 BC Value Used.
Shooter: Been using this app for 8 years or so, always been accurate. I used the DA given by the Kilo to input into the Shooter app for air density, and used the same G7 BC value (.372).

Had two targets I ranged. One at 1400 yards, the other at 760 yards. Both had wind inputs a 10 mph/90*

1400 Yards
Profile CD: 10.99 Mils elevation, 1.77 Mils Drift.
Profile G7: 11.04 Mils Elevation, 1.81 Mils Drift.
Profile G1: 11.19 Mils Elevation, 1.86 Mils Drift.
Shooter: 11.2 Mils Elevation, 1.8 Mils Drift.

760 Yards
Profile CD: 3.98 Elevation .80 Drift
Profile G7: 4.01 Elevation, .83 Drift
Profile G1: 4.06 Elevation, .86 Drift
Shooter: 4.2 Elevation, .8 Drift

Knowing that the Kilo with this particular bullet/BC has been ambitious in past (I need to dial more than it usually calls for) I tried two different "fixes".
First one was changing the G7 profile BC down to .350 from .372.

1400 Yard target: 11.55 Elevation, 1.99 Drift.
760 yard target: 4.11 Elevation, .9 Drift

Second "fix" was dropping the FPS from 2992 to 2950 while maintaining the G7 BC of .372
1400 yard target: 11.47 Elevation, 1.86 Drift
760 yard target: 4.18 Elevation, .86 Drift

Next thing I wanted to try was "calibrating" the bullet profile on the Sig by using their feature of entering drops at 2 different ranges and it'll self correct with a correction scale and FPS scale.
I entered data from the Shooter App at 1400 yards, and 1760 yards for the conditions I was in. 11.2 Mils and 17.1 Mils. It gave me a corrected FPS of 2988 and another value I didn't write down for the drop scale value. I saved and sync'd that profile, then ranged the 1400 yard target...
11.04 Mils Elevation (original was 10.99) and 1.77 Drift (same as uncalibrated)
760 Yard Target: 3.99 Mils Elevation (uncalibrated was 3.98), .81 Drift (same as uncalibrated)

Conclusions? The calibration factor for this bullet definitely didn't work.
I've shot this bullet through this rifle at distance only twice so far, have shot at 980 yards, 1200, and 1490. Everything was between .3 and .5 Mils low from the Kilo's output. On the 1200 and 1490 targets, I had two other rifles there with proven data, who'd Kilo outputs were accurate at those ranges. I've shot nearly 75 rounds for load development on this bullet over the chronograph (magnetospeed, always been accurate to within 10 fps) and know that my speeds are proven and consistent.
I need more data to get this particular bullet dialed in. It's either going to have a corrected BC value, or a correct FPS value. I suspect the BC is off on this 270 grain ELD-X as it's a fairly new bullet. However even my Shooter app hasn't been accurate on the 270's. It's been closer, but only to about half the margin of error than the Kilo. Only more time behind the gun will tell me what needs to change.

Sorry for the long winded, post, and for the lack of conclusions at the end. Data is data though...

Mike

 

[J8tnub]

Does the shooter app account for aerodynamic jump? If not you should take the wind value out of the kilo and see how much it affects your elevation.

 

[slim9300]

I assume site height is the same for both? The AB app doesn't show it on your screenshot.

Yes it is.


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[slim9300]

Do you have spin drift and Coriolis enabled on the AB app? It’s always on in the kilo. As well as Aerodynamic jump. You could try taking the wind values out and see if they match.

Did you also make sure to set the Kilo latitude to your actual latitude?

I tried it both ways and the difference was negligible.


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[slim9300]

Alright I went and ran some numbers this evening. Here's what I've found...

First, one tip:
You can override environmental inputs in the app by going to the environmental display, and tapping the orange kilo sign next to temp, pressure, humidity. You can also change wind speed and angle from here. Once you change something, you have to sync it to the rangefinder.

I also noticed my rangefinder kept bouncing back and forth between 59* and 71* between the HUD and Environmental screens. Want to check into that more, but I overrode it to 59* for the sake of testing.

I ran three different profiles in the Sig 2400. All identical except for BC "types".
Profile CD = Custom Drag Curve profile
Profile G7 = G7 BC value used
Profile G1 = G1 BC Value Used.
Shooter: Been using this app for 8 years or so, always been accurate. I used the DA given by the Kilo to input into the Shooter app for air density, and used the same G7 BC value (.372).

Had two targets I ranged. One at 1400 yards, the other at 760 yards. Both had wind inputs a 10 mph/90*

1400 Yards
Profile CD: 10.99 Mils elevation, 1.77 Mils Drift.
Profile G7: 11.04 Mils Elevation, 1.81 Mils Drift.
Profile G1: 11.19 Mils Elevation, 1.86 Mils Drift.
Shooter: 11.2 Mils Elevation, 1.8 Mils Drift.

760 Yards
Profile CD: 3.98 Elevation .80 Drift
Profile G7: 4.01 Elevation, .83 Drift
Profile G1: 4.06 Elevation, .86 Drift
Shooter: 4.2 Elevation, .8 Drift

Knowing that the Kilo with this particular bullet/BC has been ambitious in past (I need to dial more than it usually calls for) I tried two different "fixes".
First one was changing the G7 profile BC down to .350 from .372.

1400 Yard target: 11.55 Elevation, 1.99 Drift.
760 yard target: 4.11 Elevation, .9 Drift

Second "fix" was dropping the FPS from 2992 to 2950 while maintaining the G7 BC of .372
1400 yard target: 11.47 Elevation, 1.86 Drift
760 yard target: 4.18 Elevation, .86 Drift

Next thing I wanted to try was "calibrating" the bullet profile on the Sig by using their feature of entering drops at 2 different ranges and it'll self correct with a correction scale and FPS scale.
I entered data from the Shooter App at 1400 yards, and 1760 yards for the conditions I was in. 11.2 Mils and 17.1 Mils. It gave me a corrected FPS of 2988 and another value I didn't write down for the drop scale value. I saved and sync'd that profile, then ranged the 1400 yard target...
11.04 Mils Elevation (original was 10.99) and 1.77 Drift (same as uncalibrated)
760 Yard Target: 3.99 Mils Elevation (uncalibrated was 3.98), .81 Drift (same as uncalibrated)

Conclusions? The calibration factor for this bullet definitely didn't work.
I've shot this bullet through this rifle at distance only twice so far, have shot at 980 yards, 1200, and 1490. Everything was between .3 and .5 Mils low from the Kilo's output. On the 1200 and 1490 targets, I had two other rifles there with proven data, who'd Kilo outputs were accurate at those ranges. I've shot nearly 75 rounds for load development on this bullet over the chronograph (magnetospeed, always been accurate to within 10 fps) and know that my speeds are proven and consistent.
I need more data to get this particular bullet dialed in. It's either going to have a corrected BC value, or a correct FPS value. I suspect the BC is off on this 270 grain ELD-X as it's a fairly new bullet. However even my Shooter app hasn't been accurate on the 270's. It's been closer, but only to about half the margin of error than the Kilo. Only more time behind the gun will tell me what needs to change.

Sorry for the long winded, post, and for the lack of conclusions at the end. Data is data though...

Mike

Good info. Are your lower yardages (less than 600) matching perfectly?


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[HellsCanyon]

Does the shooter app account for aerodynamic jump? If not you should take the wind value out of the kilo and see how much it affects your elevation.

Good point i"ll do that. I don't believe Shooter does.

Another interesting thing, I just ran the same inputs through Hornady's web based calculator and at 1400 yards it's giving me 10.87 Mils vertical with 10.96 MILS being a "zero wind" trajectory.

I also ran the same parameters I recorded for my 1490 yard shooting session and it gives me 11.1 MILs elevation when I needed 11.5 Mils. BC has gotta be off on the 270's....

Good info. Are your lower yardages (less than 600) matching perfectly?


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I haven't ran data or shot targets less than 600 yet. Can't do it where I shoot here locally.

Mike

 

[J8tnub]

I would also use the AB custom curve when possible as those BC’s have actually been verified by AB.

 

[slim9300]

Some follow up. This is with the same settings as before but with the HUD view. It makes no sense that they match up but they do. The wind drift is a tiny bit off and I can’t explain that. It’s close enough at the end of the day. But what’s even harder to understand is that the speeds at different yardages aren’t even close. How the MOA holds match up, I have no idea.

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