Kestrel Ballistics Support Page

Most FAQ

Please review the list found here:

3rd Party Hardware and Software

We have created quick start guides for connecting to each of these below:

Vortex Fury 5000 AB Instructions

Vortex Fury 5000 AB Video Tutorial:

Kestrel 5 Series 3rd Party Hardware Connection Instructions

This guide will help with connecting a Kestrel 5700 and Bushnell 1800 Nitro rangefinder.

This document shows how you can unlock the connection issue between a Sig 5K or 10K and a Kestrel 5700 weather meter

A quick start guide to connecting a Bushnell CONX rangefinder with a Kestrel 5700 Ballistics or Elite.

A quick start guide to connecting a Leica CRF Rangemaster 3500 with a Kestrel 5700 Ballistics or Elite.

A quick start guide to connecting a Leica Rangemaster 2800 laser rangefinder with a Kestrel 5700 Ballistics or Elite.

A quick start guide to connecting a Sig Sauer 2400BDX or 3000BDX with a Kestrel 5700 Ballistics or Elite LiNK unit

A quick start guide to connecting a Steiner M830r with a Kestrel 5700 Ballistics or Elite LiNK unit

A quick start guide to connecting a Terrapin X with a Kestrel 5700 Ballistics or Elite LiNK unit.

A quick start guide to connecting a Vectronix PLRF25C with a Kestrel 5700 Ballistics or Elite LiNK unit.

A quick start guide to connecting a RAPTAR-S with a Kestrel 5700 Ballistics or Elite LiNK unit.

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Due to differences in barrel machining, muzzle breaks, propellants and other factors, when the same bullet is fired from different rifles there will be a slight difference in the drag the bullet will experience. The Hornady 4DOF solver assumes the bullet will be fired from an "average" barrel but in reality your rifle may impact the bullet slightly differently. To account for any differences the Axial Form Factor value can be modified to align the output from the solver to what your bullet is experiencing. By firing at a known target and adjusting the Axial Form Factor value till the predicted solution matches real world results, you can calibrate the solver to match your rifle and bullet and deliver even more accurate firing solutions. Axial Form Factor can be calibrated using a target anywhere from 300 to 800 yards away and impacts the solution through the supersonic, transonic, and subsonic flight of the bullet.

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Zero range is the distance from the muzzle to where a straight line following the axis of your scope crosses the flight path of the bullet. The scope is typically adjusted so this crossing point happens at 100yds but can be set further out. Because the flight path of the bullet can be impacted by changes in environmental conditions, the distance to that crossing point can vary with altitude or changes in the weather, notably if longer distance zero ranges are used. Zero Angle on the other hand is a measure of the angle between the straight line following the axis of the scope and the straight line following the axis of the rifle barrel. This angle is very small and would be difficult to measure directly but the 4DOF ballistics engine can find the angle when provided with environmental data and bullet impact location. Once the solver knows the Zero Angle between your rifle and scope a very accurate solution can be provided regardless of how long the zero range is or how much the weather changes. Read more about the Hornady 4DOF ballistics engine.

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Zero Angle is available but it is not the default option. To find Zero Angle in your Kestrel, enter the gun menu and scroll down to Zero Range (ZR) and press the center button. In the Rifle Zero sub menu, highlight Zero Range and toggle left or right. Zero Range will change to Zero Angle and a Calibrate Zero Angle command will appear below it. Selecting Cal Zero Angle will open the Zero Angle Calculator tool.

In the Kestrel LiNK Ballistics app, enter the Gun Profile Editor where you build profiles and tap the Zero Range field name in yellow. In the pop up you will see an option to switch to use Zero Angle.

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Please check out our Kestrel 5000 Firmware change log to view the differences in the various firmware versions: Firmware Change Log

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Because not all laser rangefinder manufacturers use the Kestrel Ballistics Bluetooth Protocol to talk to a Kestrel, the Hornady Kestrel cannot communicate with some rangefinders which can talk to our existing ballistics meters. Check out this page to find the latest updates on which will connect with a Kestrel 4DOF unit: 3rd Party Devices

If you have a laser rangefinder with Bluetooth LE which you would like to have communicate with one of our Kestrel meters please contact the manufacturer and ask them to implement the Kestrel Ballistics Protocol in their rangefinder.

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When calculating Zero Angle, the Hornady Kestrel asks for the distance to the Zero Target. This distance can be any distance you want but you’ll want to pick a distance where you’ll be able to accurately measure the distance between your point of aim and average point of impact with no elevation dialed or held when shooting. 100 yards or meters is a convenient distance and may be close to where your rifle is already zeroed.

Note: Just because your shooting range says a berm is at 100 yards, you should still confirm that distance with an accurate laser rangefinder or 100 yard tape measure.

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After entering the Zero Angle sub menu, select Cal Zero Angle and then follow the prompts to enter the required data for your shooting environment and target. When shooting at your zero target, make sure your scope turrets are dialed to zero elevation, don’t hold any elevation in your reticle and place the cross-hairs directly on the target (point of aim). After firing enough shots to be confident of your average point of impact, measure the distance between your point of aim and average point of impact. Enter this value in the Cal Zero Angle calculator field asking for the Impact Height at Target, (impacts above the point of aim are positive and below are negative). After calculating the Zero Angle, press Exit and when prompted, accept the Zero Angle value.

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Wind Speed – NK sells factory calibrated replacement impellers that can easily be installed by the customer. NK recommends replacing the impeller every 2-3 years depending on usage.

Humidity – The Kestrel 5 Series and DROP data loggers employ a highly accurate, calibrated, digital humidity sensor. Based on the sensor manufacturer's specifications and NK testing, drift on this sensor over time is minimal and field recalibration is likely to degrade accuracy rather than improve it. Factory calibration to validate and certify accuracy at a minimum of two RH points is available from NK. Kestrel 5000 series units can also be recalibrated in the field using our kit RH Recalibration Kit . During the five-year warranty period, NK will repair, recalibrate or replace any Kestrel 5 Series or DROP which drifts more than +/-1% RH/year since the date of manufacture.

Temperature – The thermistor in the Kestrel 5 series should not need to be recalibrated. If you think your sensor is incorrect, please contact

Pressure – The pressure in the Kestrel 5 series should not need to be recalibrated. If you think your sensor is incorrect, please contact

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Kestrel runs free Zoom training classes throughout the year on different topics. Check out the latest classes HERE

For live training at a shooting site, you can check out some of these options

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Please ensure privacy pin is not turned on. On the Kestrel, go to Main Menu->Bluetooth and press the center button. Then highlight Privacy Pin and turn off with left or right arrow. After doing this, try running the update again.

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Please try refreshing the cache on the webpage. To do this, press Ctrl-F5. If that does not work, then please try opening the order in an incognito window (Shift-Ctrl-n) . For MAC users on Safari, you can use [CMD] + [ALT] + [E]

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It will depend on if you want to integrate just the weather data or both the weather and ballistics data. If you need the ballistics (and/or weather) data, please send an email with a high level description of the project to Tech Support Email.
If you just need the weather data protocol, you can fill out our Technology Agreement found here: Kestrel Technology Agreement

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Please see our guide found here:

Kestrel Ballistics 5 Series Troubleshooting Documents

This document shows how to calibrate using CalMV and CAL DSF a 22 Long Rifle or other guns which do not shoot supersonic region.

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Please try this guidance shown here:

This guide will show a common workaround to assisting with connecting your Kestrel 5700 series unit with the Kestrel LiNK Ballistics app on an iPhone or iPad.

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Please see this navigation diagram for the Kestrel 5700 Elite

Kestrel Ballistics 5 Series Troubleshooting Documents

This guide will show the button presses to access all the various menus and submenus on the Kestrel 5700 Elite unit.

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Please try this as a workaround:

Here is a workaround if you are having issues with the Kestrel 5700 and a LiNK compatible rangefinder reconnecting.

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Every single Kestrel Meter and Kestrel DROP logger is factory tested to validate performance within specifications before it leaves our factory. We don’t rely on spot checks because we know you rely on your Kestrel to give you the accurate readings you need to stay safe, make decisions, and enjoy your activities. Each of our calibration standards is traceable to the National Institute of Standards and Technology (NIST), ensuring the highest level of reliability. Our wind/airflow standard is actually calibrated in the NIST laser doppler wind tunnel as this is the only lab in the country that can provide the calibration accuracy we require.

NK offers three types of calibration services to meet your accuracy validation needs. Each of these calibration services can be conveniently ordered through our website, allowing you to cross “Get my Kestrel calibrated” off your to-do list whenever convenient. And, ordering your calibration online creates an order history you can refer to in future. But, if you prefer, you can always call or chat with us during business hours to order your calibration. For more in-depth information about each of the services described below, simply click through to the relevant ordering page.

NIST Calibration Services

NIST Calibration is our most in-depth calibration service. The Kestrel’s measurements are compared to our NIST-traceable standard at two points after an appropriate equilibration period. The NIST Calibration Report and Certificate will show as found and as left values, standard values, acceptable range, and deviation. It will also list the date, serial number and model of the unit, desired recalibration interval, and test technician’s name and signature. NIST Calibration services can be added on to any new Kestrel purchase for customers who require it, or you may return your Kestrel to us at any time after purchase to validate its performance in detail. Please visit our Kestrel Calibration product for more information.

Factory Calibration Services

For Factory Calibration we repeat the tests performed on your unit when it was manufactured and provide a renewed Sensor Calibration Certificate confirming performance within specification, the serial number of the unit, and the signature of the testing agent. Please note that if you need more than one Factory Calibration, Tune-Ups offer a better value! Please visit our Kestrel Calibration product for more information.

Tune-Up Services

Tune-Ups include Factory Calibrations of all sensors on your unit as well as a new impeller, new battery, functional checks, cleaning and leak testing. Tune-Ups are priced at a flat $75 per unit so offer a great value if you need more than one Factory Calibration or just want to ensure your Kestrel is fully tested.

Note on Sensor Correction: If needed and available for the sensor in question, we will also restore your unit’s performance to specification by either replacing the impeller or correcting the sensor. Although not correctable, in our experience, both the temperature sensor (ambient and globe) and newer humidity sensor in the DROP and Kestrel 5 Series have proven extremely stable in performance. Every Kestrel is guaranteed to perform within specification, including the specified drift of the sensor in question, for Five Years from the date of manufacture or documented date of first customer purchase. If your Kestrel is under warranty and does not meet this standard under test, it will be repaired or replaced as covered under the terms of our Limited Warranty. If your Kestrel has an unrepairable problem and is no longer under warranty, you have the option of trading it in for a new or upgraded model under our Kestrel Trade-in, Trade-up Program. Please visit our Kestrel Tune-up product for more information.

Shipping Your Unit: After ordering a calibration or tune-up service online or via phone, please note your order number so you can add it to the outside of the box. Please pack your Kestrel securely and ship to:

21 Creek Circle
Boothwyn, PA 19061
Attn: ORDER####

You will also receive an email confirming these instructions. It is most important that we have your Order Number so we can promptly match your unit with your service request. You can also print your order confirmation and add it to the box.

Questions or clarifications about our calibration services? Email or call (610) 447-1555.

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Please see the guidance shown here:

This document shows you how you can inactivate (ie., not show) targets so they don't appear on the HUD screen.

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Even though it shows connected, something is interfering with this connection. To troubleshoot:

  1. Ensure app permissions are set in your phone's app settings
  2. Reboot your phone
  3. Do a reset on the Kestrel. Take out battery, hold down power for 30 seconds, put battery back in
  4. Try reconnecting to the Kestrel Ballistics app

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In general, there should be no special treatment needed for 22 LR compared to traditional rifle bullets if they are not being damaged during feeding. Since 22 LR projectiles are generally constructed of plated lead, they are soft and can deform easier than a traditional copper jacketed bullet during feeding or handling. If this is the case, I can believe that there would be observed differences between prediction and actual point of impact. 4DOF will handle any normal projectile dynamics that exist due to possible projectile dynamic instability that may occur at low mach numbers (transonic / subsonic).

Unfortunately, some 22 LR projectile shape’s are more prone to having dynamic instability issues than traditional copper jacketed projectiles. If the dynamic instability is severe enough (dependent upon shape, mass layout, twist, and angle of attack), it becomes impossible to predict the effects from a point of impact standpoint. Based on what I have observed with the RADAR it is possible that 22 LR projectiles will experience dynamic instability that will result in erratic point of impact results after certain time of flights that will not be able to be corrected by the shooter. The shooter is looking for a trend, I’m always hitting high or always hitting low to be able to troubleshoot, identify, and fix a problem that exists between the ballistic prediction and the observed point of impact. Unfortunately though, if impacts at 300 yds with a 22 LR are “all over the map”, this cannot be fixed by a ballistic solver.
The recommended process with rimfire would be the same as any centerfire system.

  1. Measure and input an accurate muzzle velocity.
  2. Ensure all inputs are correct pertaining to the rifle and bullet picked from the library.
  3. Conduct the find zero angle process.
  4. Shoot at distances equating to time of flights of .5-1.3 seconds (100-350 yds for most 22 LR). If there is a difference between the point of aim and point of impact, conduct the axial form factor calibration to account for the difference observed.
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When you enter the target submenu and initiate an A1st Quik Set, the following items are changed in the Kestrel 5700 unit

  • Spin Drift is set to OFF
  • Environment is set to LOCKED
  • Latitude is set to 0
  • Direction of Fire is set to 0
  • Wind is set to 3 o'clock, W1 and W2 are set to 0 and 4 mph respectively
  • Inclination Angle is set to 0
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Here's a video that shows how to calibrate the compass and has some troubleshooting tips as well: Compass Calibration ... Permalink

"All measurements not available in all units"

Temperature Functions

For best accuracy when taking temperature measurements you must keep the air moving around the temperature sensor and keep the Kestrel out of prolonged, direct sunlight. If there is a strong breeze, just point the Kestrel into the wind. If there is no wind, swing the Kestrel around in a circle on its lanyard or rapidly wave it back and forth in hand. This ensures that the sensor measures the temperature of the air rather than the temperature of the case. Alternatively, if you have time, allow the Kestrel to rest where you want to measure the air temperature (NOT in your hand or in direct sunlight if there is no wind) until the case temperature equalizes with the air temperature. When equalized, the display will read a constant value. Be aware that this could take a few minutes, particularly if there is no wind.

Humidity Functions

One reason your Kestrel may not be reading accurate ambient humidity is because of proximity to humidity sources such as your hand, your body or the ground. Avoid covering the large humidity chamber opening on the case rear with your fingers. Keep all fingers below the finger groove and away from the chamber opening. Do not take reading that rely upon humidity with the Kestrel meter lying flat – raise it into the air vertically or stand it on its base and orient it into the wind or air flow. If a high level of accuracy is required for measurements involving humidity, do not hold the unit while taking measurements. Taking readings with the Kestrel in your hand or over your body can raise relative humidity by 5% or more. A Kestrel vane mount will isolate the Kestrel Meter from erroneous humidity influences and keep it oriented into the wind or air flow while taking measurements. Whenever you move your Kestrel Meter into a new environment wait until the primary sensor values have stabilized (Temperature, Humidity, etc.) before taking measurements that rely upon these values. After a large change in environmental condition, this may take 15 minutes or more, with humidity potentially taking the longest. If the humidity sensor housing (located above the rear label) is wet, the Kestrel cannot take an accurate humidity reading. If the sensor does become wet, shake the unit vigorously to remove the water, and then let it dry completely before use. If the sensor comes in contact with salt water, rinse it thoroughly with clean water, then shake it and allow it to dry. As is typical with humidity sensors, it is possible for the humidity sensor in the Kestrel to drift over time as described in the spec sheet. If your unit has a Humidity recalibration function, it can be returned to the factory or used with the Kestrel RH Calibration Kit to recalibrate its humidity readings.

Wind Meter Functions

Wind speed is highly dependent on surrounding obstructions such as buildings, yourself and the ground, with wind speeding up as it flows around and over obstacles and slowing down as it passes behind them. Even in an open area, Wind speed will be slower near the ground so ensure you are taking measurements at an appropriate height for your application. Hold the back of the unit directly into the wind. Holding the unit off-axis by 5° will reduce accuracy by 1%, 10° will reduce accuracy by 2% and 15° will reduce accuracy by 3%. Using a Kestrel Vane Mount will ensure the unit is correctly oriented into the wind and measuring accurate wind speeds. The Kestrel impeller housing can rotate in the unit. For best accuracy, ensure one of the three “arms” of the impeller housing is pointing straight up. The wind speed displayed by the Kestrel Meter is a 3 second rolling average. This allows the unit to provide a value that is more representative of the typical, ambient conditions but not capture peak speeds for instantaneous blasts of air.

Compass Functions

The compass in the Kestrel Meter is used for direction, crosswind, headwind/tailwind as well as for capturing various user inputs based on direction. When calibrating and when using the compass, it is important to hold the unit as vertically as possible. Any tilt in angle present when the unit is calibrated or when measurements are taken will negatively impact the accuracy of the compass reading. Many users will inadvertently tilt the Kestrel Meter away from themselves slightly when holding the unit. If a high level of accuracy is required, using a Kestrel vane mount on a leveled tripod for calibration and measurement can eliminate error.

Pressure Functions

All pressure and altitude measurements are made using the pressure sensor. Some units have a dedicated “Pressure” screen which shows Station Pressure, the raw pressure reading straight from the sensor. The Barometric Pressure measurement (Baro) displays the local Barometric Pressure using the Station Pressure measurement adjusted to the local altitude using the Reference Altitude value input by the user. The Altitude measurement displays the local altitude using the Station Pressure measurement combined with the Reference Baro value input by the user. To obtain an accurate barometric pressure or altitude readings, you must first know EITHER your location’s current barometric pressure OR your current altitude. If the Reference Altitude value is incorrect, the Barometric Pressure reading will also be incorrect. If the Reference Barometric pressure value is incorrect, the Altitude reading will also be incorrect. Because Barometric Pressure and Altitude are each dependent on the alternate reference value remaining constant, Barometric Pressure and Altitude cannot be accurately measured simultaneously. If your unit has a pressure recalibration function, a new Barometric Pressure calibration value may be input. If this value was not taken from a verified source (a local airport or weather station) with the Kestrel being calibrated at the same location as the reference device, pressure related measurements may be incorrect.


When changing environments (such as moving form an air conditioned room to outdoors or removing the unit from your pocket) the unit requires between 8-15 minutes to equilibrate to its surroundings before taking readings. Take measurements at least 3 feet off the ground and in the same wind or air flow conditions as the people you are monitoring. Ensure the Kestrel is oriented into the wind and able to measure the full wind value. A tripod or pole mount and the Kestrel Rotating Vane Mount are ideal for ensuring accurate measurements. Differences in the reflectivity of ground surfaces such as grass or asphalt will impact measurements. Be sure to take measurements in the same solar/radiant heat environment as the people you are monitoring. Unlike best practices for other measurements, WBGT is intended to be taken in direct sunlight. As long as there is occasional wind the Kestrel has software that allows it to maintain an accurate WBGT reading despite being placed in direct sunlight.

Air Flow

Kestrel Professional Meters can calculate air flow through a duct by combining user input information about the size and shape of the duct with the measured air velocity. In addition to reading the instantaneous Air Flow off the main measurement screen, a more accurate result may be obtained by capturing an average air flow on the Min/Ave/Max screen while traversing the duct. Traversing consists of dividing the area of the duct into evenly sized sections and averaging the air flows at the center of all sections. By spending an equal amount of time at each measurement location and quickly moving between measurement locations, the average air flow measurement can provide a more accurate measure of the air flow in the duct. Capturing an average can be particularly helpful when measuring ducts with registers or dimensionally uneven air flow.

Air Flow Diagram

Evaporation Rate

(Kestrel 5200 Professional Environmental Meter) Kestrel Professional Meters can calculate a concrete evaporation rate (ACI 308) by combining a user input concrete temperature with measured air temperature, wind speed and relative humidity. Concrete mix temperature is generally measured with a probe or infrared thermometer and should be read at the time of making the evaporation rate measurement After inputting the mix temperature, hold the unit vertically, approximately 20 inches above the surface of the concrete while facing the rear of the unit directly into the wind. To avoid inaccurate Evaporation Rate readings due to thermal loading it is best to shade the Kestrel. (Be sure the source of shade is not obstructing the wind speed measurement.) The ACI recommends taking a 6-10 second average of the evaporation rate to account for fluctuating wind speeds. To measure an average Evaporation Rate, scroll right from the Evaporation Current Measurement Screen to the Min/Ave/Max Screen and press select to manually start and stop a capture.

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Yes. You can use the red "capture" button to easily delete letters and the backlight button to add blank spaces to the names.

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Please see our guidance in this tutorial on Accy 1st features:

This is a quick guide that shows you how to use the Accuracy 1st menu options for the Kestrel 5700 Elite (fw 1.35 or higher needed)

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You will first need to create an account if you do not already have one. After you create an account, sign in. Click on your account name at the top of the page and select My Account. On the left of the screen, you will see Product Registration, select this option. Enter your purchase date, serial number and product name into the fields and then select Save.

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