Inaccurate Kestrel Readings???

[Timmeh6mm]

Was at a local match after I chrono and zero'd then began shooting the match, first 3 stages bombed all shots are high... compared to another shooters kestrel the only Difference between both of our dope and rifles was Bore Height and MV however the output dope was almost .3 off @300 yards.... none of us can figure out whats going on...

Heres the data from today from what i can remember.... its gonna be a long thread but i need help.

54*F
1054 Elevation
DA 1500
Avg wind speed 17 gusts to 25
humidity 45%
Press 29.92

***DATA IN KESTREL***

MV ~ 3041 SD (8.3) ES 14
Barrel 26" 1:7.5
Hornaday 6CM 108 ELD factory ammo
Bore Height 2.10
Zero 100y
no offsets
G1 BC .536
Bullet Diameter .243

Where i noticed something was wrong when 300 yard targets i was missing high and still having to come down from what the kestrel gave. @306yrds wind 8:30 oclock 15mph kestrel says 1.03 i miss high actual center impact was .8
another shooter was also shooting 6creed and his MV was only 6FPS faster than i was shooting, and all of his data was pretty much .2 lower than what i was getting.

Ive put this same exact data into ballistic ARC using all the same Atmospheric data and got .8 @300
Same data using JBM Ballistics and still getting .8 for 300 and on..

now im no ballistics guru but with 0 wind in the kestrel i get the correct elevation on all ranges... but soon as i add wind into the equation it jumps .2/.3 has anyone experienced this before??

306yd 1.0 actual .8
509yd 2.4 actual 2.2

From the week before

1000 7.4 actual 6.8
1100 8.8 actual 8.3

 

[ken4570tc in WY]

I don't mean to sound like a dumb shit but I checked the Krestel owners manual and indeed it calls for 'Bore Height'. Since the bore is below the scope, shouldn't that be a negative value. I couldn't find sample data input on the web. I use Strelok Pro.

 

[Tnc]

Are you using wind 1 or wind 2? I’ve seen this happen when using wind 1. Zero wind 1 and input your wind values in wind 2 only. See if that helps.

 

[surprise]

Great advice

 

[Kestrel Ballistics]

if you have a 5700 why not use the G7 and if you have an Elite use the custom curve, the bullet is in the library. Next do a muzzle Velocity calibration to true the Kestrel to your results. Get the Kestrel optimized first, then chase problems.

 

[8up]

I don't mess with the wind setting in the Kestrel at all. Keep it set to zero. Use only the meter to get a wind reading, practice your wind calls and wind holds

 

[Nik H]

Are you using wind 1 or wind 2? I’ve seen this happen when using wind 1. Zero wind 1 and input your wind values in wind 2 only. See if that helps.

That is what I do or AJ is factored in. I also turn off all of the other shit...SD, etc.

 

[AbbyKatt]

I've become a great fan of creating an MV Temp table. Last week all my shots were hitting about a mil high. When I checked my gun profile on the Kestrel, my MV Temp table had been turned off. After turning the table on, the Kestrel outputs all came down that mil. It was really eye opening to see the system work!

 

[Diver160651]

if you have a 5700 why not use the G7 and if you have an Elite use the custom curve, the bullet is in the library. Next do a muzzle Velocity calibration to true the Kestrel to your results. Get the Kestrel optimized first, then chase problems.

At 300 BC can NOT be the issue. BC takes longer to effect change than gravity at 300..

Drop at 300 is a MV issue, it is one of the great distances to confirm because wrong BC effects are so little. Look for some other zero “offset” programmed in by the user or a glitch.

Now if the user but a g7 value in, but has G1 selected ~ that’s a different issue.

 

[8up]

If I had my hands on the Kestrel, could find what setting is causing the issue. As long as the settings are set correct, it will give you a accurate elevation hold. Something is off with it. Abbykat might have one, the MV temp table either off or on, another possible was when you trued the Kestrel, environmentals that day as compared to match day, or there is a error in the trueing process.

Not trying to slam the OP, just reducing the possible variables.

 

[clcustom1911]

MV temp or zero offset has fucked me up in the past before I really took the time to go through all the menus and items and found out exactly what they meant and how to adjust them. I got my 4500NV used and it didn't have the manual.

@Lowlight did a post or blog entry on the importance of zero offset and obtaining a no-shit zero for your rifle/ammo.

 

[morganlamprecht]

this is why the majority of us zero out wind speed 1 like mentioned above so it removes ABs AJ functionality...i made a thread about it a few years ago, and lots of people had the same issues

good luck ever getting your dope to line up day to day using the winds in AB...zero out wind speed 1 before getting elevation data and your headaches will go away

 

[seansmd]

Another thread where folks are trying to correlate kestrel data and folks asking for specific settings. It would be nice, especially for the models with link to have settings dump option. For these instances or saving with your written dope.

 

[blbennett1288]

All good information! I was having the same issue with my Kestrel not matching BallisticsARC or 4DOF. I suspect it is the MV temp of AJ due to wind1

 

[Hollywood 6mm]

I don't mean to sound like a dumb shit but I checked the Krestel owners manual and indeed it calls for 'Bore Height'. Since the bore is below the scope, shouldn't that be a negative value. I couldn't find sample data input on the web. I use Strelok Pro.

No, it's a positive value, at least in all of the AB programs.

 

[Timmeh6mm]

if you have a 5700 why not use the G7 and if you have an Elite use the custom curve, the bullet is in the library. Next do a muzzle Velocity calibration to true the Kestrel to your results. Get the Kestrel optimized first, then chase problems.

im using a 5700 non elite. ive even completely cleared out my device and used the G7 which hornaday calls for a .270 and the kestrel library on my app uses a .267 and results have not changed with. i am still getting higher solutions by .2/.3 MV is 3041 and trued MV for actual impacts at 1100yds was 3112 but using that trued MV inside 800 impacts were very high at the top edge of the target. im using factory horaday 108's

 

[RSB4]

Was at a local match after I chrono and zero'd then began shooting the match, first 3 stages bombed all shots are high... compared to another shooters kestrel the only Difference between both of our dope and rifles was Bore Height and MV however the output dope was almost .3 off @300 yards.... none of us can figure out whats going on...

Heres the data from today from what i can remember.... its gonna be a long thread but i need help.

54*F
1054 Elevation
DA 1500
Avg wind speed 17 gusts to 25
humidity 45%
Press 29.92

DATA IN KESTREL

MV ~ 3041 SD (8.3) ES 14
Barrel 26" 1:7.5
Hornaday 6CM 108 ELD factory ammo
Bore Height 2.10
Zero 100y
no offsets
G1 BC .536
Bullet Diameter .243

Where i noticed something was wrong when 300 yard targets i was missing high and still having to come down from what the kestrel gave. @306yrds wind 8:30 oclock 15mph kestrel says 1.03 i miss high actual center impact was .8
another shooter was also shooting 6creed and his MV was only 6FPS faster than i was shooting, and all of his data was pretty much .2 lower than what i was getting.

Ive put this same exact data into ballistic ARC using all the same Atmospheric data and got .8 @300
Same data using JBM Ballistics and still getting .8 for 300 and on..

now im no ballistics guru but with 0 wind in the kestrel i get the correct elevation on all ranges... but soon as i add wind into the equation it jumps .2/.3 has anyone experienced this before??

306yd 1.0 actual .8
509yd 2.4 actual 2.2

From the week before

1000 7.4 actual 6.8
1100 8.8 actual 8.3
[/QUOT

Watch your BC. IVE SEEN it many times where the elivation was wrong because of a incorrect BC. You may have to adjust your BC and ensure the MV line up. Just because the BC is posted does not mean it’s correct. What G scale are you using? I turn the wind values off in my for a number of reasons but the main reason is I can only gather wind at my location.

 

[DocUSMCRetired]

More than likely the two culprits here are Muzzle Velocity and Aerodynamic Jump Zero Bias.

 

[blbennett1288]

Is the muzzle velocity temp table only in the KestrelLiNKBallistics App? I cant seem to find it in my 5700 Elite

 

[DocUSMCRetired]

Is the muzzle velocity temp table only in the KestrelLiNKBallistics App? I cant seem to find it in my 5700 Elite

It is in the device as well. Press enter on "Gun" then enter on "MV" and scroll down.

 

[blbennett1288]

It is in the device as well. Press enter on "Gun" then enter on "MV" and scroll down.

thank you, found it!

 

[Bulldog Firearms]

More than likely the two culprits here are Muzzle Velocity and Aerodynamic Jump Zero Bias.

How do you address those two isses, I have the same issues going on where my data is often .2 to .3 low from actual data?

 

[Bulldog Firearms]

Went and shot a match today. Kestrel was off by half a mil at 1k. Ended up putting atmospherics in JBM and running ballistics that way and they lined up perfectly. A little disappointing for a $600 piece of hardware.