Knowledge Base

4DOF is a ballistics engine created by Hornady for their bullets as well as other common long range bullets made by other manufacturers. The 4DOF solver utilizes a modified point mass solution which models bullet flight in 4 degrees of freedom to provide incredibly accurate trajectories to extremely long ranges. The software does not use Ballistic Coefficients (BC), but instead utilizes Drag Coefficient versus Mach number data measured with a Doppler radar for each projectile. While the 4DOF solver does not use traditional ballistic coefficient numbers, the Kestrel 5700 with Hornady 4DOF also includes a traditional G1 & G7 ballistics engine for use with bullets which don’t have a 4DOF bullet file available.

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.

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.

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.

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

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.

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.

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.

The Kestrel LiNK Ballistics app works with all of our Kestrel Ballistics meters. It recognizes the exact meter that you are currently connecting and changes to match that Kestrel.

We changed the way that the rifle twist is entered with firmware 1.20 and higher. If you have an 11 inch rifle twist, please enter this as 1:11.00 in. This is read as a 1 rotation in every 11 inches of barrel travel. Previously this was just entered as 11.00 in. If instead you have a 9 inch twist, it would be entered as 1:9.00 in.

The Kestrel 5 Series models can store over 10,000 data sets.

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 techsupport@nkhome.com

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

Kestrel 5 series units with LiNK will need to use the Kestrel LiNK Wireless Dongle to connect with a computer. The Kestrel 5 series will not work with any internal Bluetooth modules. To connect, insert the Kestrel LiNK Dongle into an open USB port. On the Kestrel, go to the Main Menu->Bluetooth and turn it ON. Set Conct to "PC / Mobile." Open the application on the computer and select the Kestrel as the device to connect to. There is no more “pairing," "COM port numbers," or "PIN Codes" to worry about for those familiar with the 4000 series.

Please see our guide for this Bluetooth issue:

Please see our graphing guide:

If you are getting NaN shown as a solution, then you have a bad value in your gun profile. For instance, the bullet length is set to 0.000. This also confirms that you have an older version of the firmware as later versions will check for these conditions before loading the gun on the unit. Check your profile and update your firmware to resolve this issue. If you are getting Bad Enviro as a solution, then there is an issue with one of the sensors. If the issue persists, then there might be a sensor failure. The best course of action is to fill out a Kestrel Service request and send it in.

Var is going to be the magnetic declination of your current location, further information can be found here: Magnetic Declination
Var is not used when selecting Magnetic North. If you choose True North, then it is advisable to add the Var number.
To find your magnetic declination, here is a good place to start Find my Var

The free Kestrel LiNK Ballistics app for Android and iOS is the ideal companion to the Kestrel 5700 Ballistics series of Weather Meters. Build and manage your gun/bullet profiles and download them to your Kestrel Ballistics unit before you set out. The app is also the perfect way to display your ballistic solutions remotely via Bluetooth. Another option is purchasing a Kestrel HUD

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.

Here is a list of the changes for Kestrel firmware version 1.49

Sight Scale Factor - For Scope Corrections   (Size: 156.9 KB)

Here is a tutorial on entering Sight Scale Factor (SSF) also known as a scope correction factor into the Kestrel.

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]

Make sure Bluetooth^® is turned ON on your phone. On the Kestrel, go to the Main Menu->Bluetooth and turn it ON. Press the center button while Bluetooth is highlighted and check to ensure that Conct is set to PC/Mobile and it shows Available. Next go to the application that you are connecting with on your phone and select the Kestrel as the device you would like to connect with. Please note: if you do not find the Kestrel on your phone’s “standard” Bluetooth connection screen, that does not mean that the Kestrel is not working properly. Please first go to the application and try to connect through the application. The Kestrel should connect.

Our article Understanding Pressure, Altitude and Density Altitude talks about Altitude and Barometric Pressure in great detail. The article also describes how to utilize your Kestrel to take these measurements.

The true distance to target should be entered, as reported by a laser range finder or whatever other means the operator is using to get range to target. See below:

To UPDATE your firmware on any Kestrel you can use the appropriate link below:

Please click here to see our 3rd party applications

No the DROP will not connect with the Kestrel LiNK Ballistics app. The app does not have a ballistic solver in it so you need to have a 2700 or 5700 in order for it to work correctly. However there are other 3rd party apps that will work with the DROP. Here is a list of them: 3rd Party Apps

Please try this guidance shown here:

Fixing Connection Issues with an iPhone or iPad with Kestrel LiNK Ballistics   (Size: 560.8 KB)

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.

Please check out our tutorial:

Please try this as a workaround:

Troubleshooting reconnection issues with compatible laser range finders   (Size: 355 KB)

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

Please see this guidance:

Kestrel 5700 with Hornady 4DOF Downloads

How to Calculate your Axial Form Factor   (Size: 111.2 KB)

Guidance on how to properly adjust your Axial Form Factor

The free Kestrel LiNK Ballistics app is the perfect companion to the Kestrel Sportsman, Kestrel 5700 Ballistics Weather Meter, Kestrel 5700 Elite Weather Meter with Applied Ballistics, Kestrel 5700 Ballistics Weather Meter with Hornady 4DOF, or Kestrel 2700 Ballistics Weather Meter. Build and manage your gun/bullet profiles and download them to your Kestrel Ballistics Meter before you set out. At the range or match, secure your Kestrel Ballistics Meter to a tripod using the optional Kestrel Vane Mount and use the LiNK Ballistics app to quickly adjust the target range and direction of fire and view the shooting solution and wind rose without leaving your shooting position. It’s like having a meteorologist and ballistician standing next to you while you shoot.

Download Kestrel LiNK Ballistics for iOS:

Quick Look

• Wirelessly adjust the target range and/or direction of fire on your Kestrel and view the resulting elevation and windage solution without ever leaving your shooting position.
• Build and transfer custom gun/bullet profiles.
• Comprehensive Applied Ballistics bullet library provides G1/G7 ballistics coefficients, weight, diameter, and length data for over 500 bullets.
• Comprehensive Hornady Bullet Files that include the bullet's mass properties, aerodynamic moments, and Doppler Radar determined drag coefficients (Kestrel 5700 4DOF only)
• With Kestrel Elite Meters, also access and use Applied Ballistics Custom Drag Models, providing exact drag profiles for supersonic, transonic, and subsonic bullet flight for maximum accuracy at extreme long range.
• Advanced Target Card view allows you to simultaneously view the elevation and windage solution for up to 10 targets defined by direction, range, and angle - giving you the edge at precision rifle matches (available for Kestrel Elite only).
• Export your customized target card to save or print out.
• Use your phone's compass to capture a new direction of fire, wind direction, or inclination angle and send it to the Kestrel.

Example Screen Shots

	See elevation and windage solutions as well as wind speed and direction without leaving your shooting position. Changing Target Range and/or Direction of Fire in the app automatically updates the solution from the Kestrel remotely.
	Input up to 10 separate target ranges to see elevation and windage solutions for each. Perfect for competition multi-target stages.
	Create and manage gun and bullet profiles for easy upload to and from your Kestrel. Includes bullet data from the Applied Ballistics G1/G7 bullet library.

Kestrel Firmware:

Support Documents for all Kestrels

Kestrel 5000 Firmware Update Change Log   (Size: 583 KB)

Version 1.53/2.11

Device Compatibility:

• Firmware: iOS versions 10.0 and higher.
• Hardware: iPhone 4s onward, iPad 3rd generation onward, iPod Touch 5th generation onward.

Kestrel Compatibility:

• Kestrel Sportsman Weather Meter with Applied Ballistics with LiNK
• Kestrel 5700 Ballistics Weather Meter with LiNK
• Kestrel 5700 Elite Weather Meter with Applied Ballistics with LiNK
• Kestrel 5700 Ballistics Weather Meter with Hornady 4DOF
• Kestrel 2700 Ballistics Weather Meter

The free Kestrel LiNK Ballistics app is the perfect companion to the Kestrel Sportsman, Kestrel 5700 Ballistics Weather Meter, Kestrel 5700 Elite Weather Meter with Applied Ballistics, Kestrel 5700 Ballistics Weather Meter with Hornady 4DOF, or Kestrel 2700 Ballistics Weather Meter. Build and manage your gun/bullet profiles and download them to your Kestrel Ballistics Meter before you set out. At the range or match, secure your Kestrel Ballistics Meter to a tripod using the optional Kestrel Vane Mount and use the LiNK Ballistics app to quickly adjust the target range and direction of fire and view the shooting solution and wind rose without leaving your shooting position. It’s like having a meteorologist and ballistician standing next to you while you shoot.

Download Kestrel LiNK Ballistics for Android:

Quick Look

• Wirelessly adjust the target range and/or direction of fire on your Kestrel and view resulting elevation and windage solution without ever leaving your shooting position.
• Build and transfer custom gun/bullet profiles.
• Comprehensive Applied Ballistics bullet library provides G1/G7 ballistics coefficients, weight, diameter and length data for over 500 bullets.
• Comprehensive Hornady Bullet Files that includes the bullet's mass properties, aerodynamic moments and Doppler Radar determined drag coefficients (Kestrel 5700 4DOF only)
• With Kestrel Elite Meters, also access and use Applied Ballistics Custom Drag Models, providing exact drag profiles for supersonic, transonic, and subsonic bullet flight for maximum accuracy at extreme long range.
• Advanced Target Card view allows you to simultaneously view the elevation and windage solution for up to 10 targets defined by direction, range and angle - giving you the edge at precision rifle matches (available for Kestrel Elite only).
• Export your customized target card to save or print out.
• Use your phone's compass to capture a new direction or fire, wind direction, or inclination angle and send to the Kestrel.

Example Screen Shots

	See elevation and windage solutions as well as wind speed and direction without leaving your shooting position. Changing Target Range and/or Direction of Fire in the app automatically updates the solution from the Kestrel remotely.
	Input up to 10 separate target ranges to see elevation and windage solutions for each. Perfect for competition multi-target stages.
	Create and manage gun and bullet profiles for easy upload to and from your Kestrel. Includes bullet data from the Applied Ballistics G1/G7 bullet library.

Kestrel Firmware:

Support Documents for all Kestrels

Kestrel 5000 Firmware Update Change Log   (Size: 583 KB)

Version 1.53/2.11

Device Compatibility:

• Firmware: Android 5.0 and higher.
• Hardware: Most Android Devices with Bluetooth Smart®, including Samsung Galaxy, Nexus 4, Motorola Droid and other recent generation phones and tablets.

Kestrel Compatibility:

• Kestrel Sportsman Weather Meter with Applied Ballistics with LiNK
• Kestrel 5700 Ballistics Weather Meter with LiNK
• Kestrel 5700 Elite Weather Meter with Applied Ballistics with LiNK
• Kestrel 5700 Ballistics Weather Meter with Hornady 4DOF
• Kestrel 2700 Ballistics Weather Meter

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.
... Permalink

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.

WBGT

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.

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.

Please see this guide:

Please see this guidance

Changing Direction of Fire and have Wind Direction Change   (Size: 147.6 KB)

This tutorial will show you how you can now change DOF and have your Wind Direction change. This setting can be found in all 5700s with firmware version 1.41 (or higher).

The attached link will help with determining average wind direction and the use of a wind rose. The documents would be pertinent to any of the 5500 models, especially important for spray drift and measurements in the protected zones.

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

Please see the guidance shown here:

Target Estimation Shortcuts with Kestrel 5700   (Size: 221 KB)

This document shows how to estimate either Target Range or Target Speed by just using your Kestrel 5700 and your scope.

As can be seen in the pictures below, place your thumb on the bottom of the unit and slide the latch from the “Locked” to the “Unlocked” position. The battery door should pop up enough that you can remove it. If you have trouble opening the battery door, some slight pressure DOWN on the battery door itself with your other thumb may help release the latch.

First slide in the tab at towards the top of the unit, then gently press the bottom part of the battery door down until it snaps into place.  Ensure that the O-ring remains in place on the battery door when closing.

Typically this will happen if the Kestrel is placed near a magnet or magnetic source. Things such as the MagnetoSpeed Riflekuhl or other chamber chillers, electronic hearing protection, or maybe even magnetic buttons on your pocket. Any magnet can affect the compass calibration. Also storing the Kestrel in a metallic enclosure such as a gun safe can have an affect on the compass calibration.

No. You can only pair the Kestrel to the Kestrel LiNK Ballistics app as a one-to-one connection. You can connect to a laser rangefinder and the Kestrel HUD simultaneously however.

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.

A bullet file is the exact physical model of the projectile that includes the bullet's mass properties, aerodynamic moments and Doppler Radar determined drag coefficients. By having the exact shape and mass distribution of the bullet along with the aerodynamic moments and drag coefficients for that specific bullet, 4DOF can accurately model the dynamic flight characteristics and provide an incredibly accurate trajectory solution. This exact modeling of the projectile allows us to predict drop, wind drift, projectile Gyroscopic Stability Factor (Sg) as a function of range, yaw of repose and corresponding prediction of spin drift, aerodynamic jump due to a cross wind, and limit cycle yaw at extended ranges due to Magnus effects.

NK strongly recommends continual use of Lithium AA batteries in your Kestrel.  Lithium batteries respond best in extreme temperatures and help prevent against any corrosion.  Customers can also use Alkaline or Nickel Metal Hydride (NiMh) if they prefer, but we recommend turning “Auto Store” to “OFF” when placing these units in storage to minimize the drain on the battery.  Also, please make sure you set the System->Battery setting to match the type of batteries that you are using.

Please see this guide:

Kestrel 5700 with Hornady 4DOF Downloads

How to Connect a Kestrel 5700 with Hornady 4DOF to Kestrel LiNK Ballistics App   (Size: 227.9 KB)

Quick guide on connecting a Kestrel 5700 with Hornady 4DOF to the Kestrel LiNK Ballistics App

Please see this guide:

Kestrel 5700 with Hornady 4DOF Downloads

How to Create and Transfer Bullet Files with Kestrel LiNK Ballistics App   (Size: 444.1 KB)

Quick tutorial on how to create and transfer gun profiles for Kestrel Hornady 5700 4DOF units

Please see this guide here:

How is Bullet Length Calculated?   (Size: 1.1 MB)

A quick diagram of how to measure bullet length

Please see this guide on how to update your Kestrel Firmware using Windows:

Please see this guide for updating Kestrel 5000 series units with MAC/OSX:

No. Currently ONLY the Kestrel Sportsman Weather Meter with Applied Ballistics or the Kestrel 5700 Ballistics Weather Meter can be upgraded to the Kestrel 5700 Elite model.

Make sure on the Kestrel you go into Environment and set Wcap to All Targets instead of One Target

All of the Kestrel 5000 series units have the Night Vision option in addition to the standard white backlight.  There is a menu selection that allows the customer to toggle between both options.

Yes. You can always trade-in an older Kestrel, regardless of its condition, by using our Customer Trade-In Program.