Welcome to the SIG SAUER BDX Support page. Below you can view our FAQ, register the warranty or download the current owners manual for your KILOBDX or SIERRA3BDX product.



SIG BDX App 01 Pairing Bonding

SIG BDX App 02 Ballistic Profiles

SIG BDX App 03 Rangefinder Settings

SIG BDX App 04 Sights Settings

SIG BDX App 05 Ballistic Holds Settings


SIG BDX App 07 Muzzle Velocity Calibration

SIG BDX App 08 Rangefinder Only


You need to adjust the diopter ring to your vision. Rotate the eyecup / diopter ring in either direction until the display comes into sharp focus.

Your KILO will perform differently based on changes in ambient conditions such as bright sunlight or snow, rain or fog, temperature and the reflectivity of the target being ranged. For example, at dusk and dawn your rangefinder may be able to range trees at over 1000 yards but in bright sunlight may only achieve 500 yards. If your KILO will not range at least 400 yards under normal conditions (fog and rain excluded) please contact customer service. Your product may have fallen out of alignment.

Delete the BDX App from your smartphone. Download and reinstall on your phone. Make sure you have a fresh battery in your KILO. Relaunch the App, turn on your KILO and repeat the Pairing instructions in this manual.

Click here for iPhone
Click here for Android

Most rangefinders will provide over 4000 individual range calculations using a fresh CR2 primary lithium battery. Your KILO exceeds this specification. When heavily using SCAN mode the battery may appear to drain faster since your KILO is ranging 4x per second in HyperScan mode. This is normal operation but you should keep a spare CR2 battery when heading out to remote locations.

For accurate ballistic solutions make sure you have updated the temperature and altitude within the App to your current location, you have the correct bullet caliber (diameter) and weight selected, your zero distance is correct and that your muzzle velocity is correct. Using the MV Calibration routine provides the most accurate MV and will improve the accuracy of the ballistic calculator. It is always best to use the MV Calibration routine at the farthest distance you intend to shoot. Calibrating at 500 yards will yield a better MV than calibrating at 200 yards.

Try the following: (1) turn Bluetooth OFF, then back ON on your phone, (2) remove the batteries from your scope and rangefinder and reinstall, and / or (3) close the BDX App and relaunch it.

Press “Scan for Devices” in the upper right hand side of the screen. Any active devices that are powered on will show up in white below the icons.

You likely need to adjust your muzzle velocity by either chronographing your rifle or using the MV calibration tool built into the BDX App. The MV calibration can be done by clicking on the target icon located next to the MV on the RANGEFINDER page or in the reticle image on the SIGHTS page.

When you PAIR with a rangefinder or sight, you may have a mandatory firmware update. Go to the RANGEFINDER page or SIGHTS page and you will be prompted to update your firmware. Make sure your KILO or SIERRA is turned on before pressing the UPGRADE button on your App. If for any reason the firmware update doesn’t complete you can close the App, go back into the RANGEFINDER or SIGHTS page and restart the update.

Check to make sure the riflescope has good batteries and is turned on (you should see an illuminated reticle). Launch the BDX App and check on the SIGHTS page to make sure the ballistic reticle is turned OFF. Your SIERRA3 should be paired and bonded with a BDX KILO for the blue LED indicator on the power selector ring to be turned on. Also, if you enabled battery saver mode in the BDX App the blue PSR LED indicator will shut off when the batteries drop below 25% capacity.

This is typical after turning on for the first time. The slow blink means it is advertising its Bluetooth ID for pairing to the BDX App or a KILO. The LED is solid when paired and bonded with an active KILO; the KILO must be in ABU mode and the ballistic reticle must be turned OFF. When a new ballistic holdover value is calculated and passed to the SIERRA the blue PSR indicator will flash quickly to confirm it received the solution and then return to solid. If you exceed the maximum range on the Bluetooth modules on your paired and bonded KILO the blue PSR indicator will return to slow flashing.

You are prompted to enter a 2-digit PIN code when pairing with a KILO using the BDX App. Enter “76” in this case into your phone and hit enter. A dialog pop-up box at the bottom of the App screen will confirm that this PIN code is correct and your KILO will be formally paired and authenticated to your phone.

If your KILO and a Kestrel are actively paired (sending / receiving information) the BDX App cannot be connected and paired to your KILO at the same time.

To display a complete ballistic solution your KILO must be actively paired with a Kestrel. No holdover information is displayed unless the Kestrel and KILO are both on and actively paired.

AB External mode on your KILO was designed to be used directly with a Kestrel with AB Elite on board. This communications protocol is relatively slow and does not respond quickly as compared to using AB Ultralight. AB Ultralight resides on your KILO and is much faster for calculating ballistic solutions out to 800 yards.

You need to setup at least one custom bullet profile on your Kestrel. See the Kestrel instructions for setting up a bullet profile.

It is possible that your AB license in the KILO was not provisioned. Please call Sig Sauer customer service – we can help you unlock your KILO AB License.

Wind holds can be symmetrical (both sides) or directional (one side). You can configure this setting in the BDX App - SIGHTS menu - Settings. Set the wind holds to symmetrical if you just want a standard cross wind setting but are not sure which way the wind might be heading.