User test: SIG Sauer Kilo 1800 BDX rangefinder and Sierra3 BDX 4.5-14x44 riflescope in hunting use

Quick reticle quick adjustment, or ballistic turrets, have been integrated or can be retrofitted into nearly all hunting and sporting optics by any manufacturer for several years. These devices allow the hunter or sports shooter to reliably and accurately adjust the aiming point at various ranges.

Originally, such optics quick adjusters were developed for the military, where sniper scopes are equipped with vertical and horizontal adjustment turrets to provide quick and accurate adjustment capability for the various ranges. Snipers use a second person to determine the range and correct the elevation and windage reticle positions. Unlike military optics, hunting optics use only the elevation adjustment of the turret. The range measurement is performed by means of a rangefinder. Manual adjustment is then performed on the reticle.

SIG Sauer has digitized this manual step with the BDX system. The Kilo 1800 BDX rangefinder measures and processes the distance, angle and atmospheric conditions. The determined data is then immediately transmitted to the scope via Bluetooth. The aiming point correction is determined automatically beforehand. The prerequisite for this is the ballistic data and the load used, which are calculated using the SIG Sauer app on the smartphone. The illuminated dot in the reticle now moves to the determined distance and you simply zero your rifle.

SIG Sauer Kilo 1800 BDX: fast target system setup

The SIG Sauer Kilo 1800 BDX
The SIG Sauer Kilo 1800 BDX also works reliably as a laser rangefinder without the BDX scope, of course.
SIG Sauer Kilo 1800 BDX details 
Just one click on the top button and the SIG Sauer Kilo 1800 BDX data acquisition is done.

We zeroed the rifle at 100 meters: the initial setup as well as programming of the Kilo 1800 BDX rangefinder is done via smartphone using the free SIG Sauer BDX app, which is only needed afterwards when changing ammunition or making other changes. The ballistic data of many loads are stored in the app and are also kept up to date by means of updates. Here you simply select your suitable ammunition. The muzzle velocity should also be specified here, otherwise you can also correct the point of impact at 200 and 300 meters by changing the velocity until it fits. Of course, this can only be done on the shooting range.

Nothing is changed on the scope itself after the 100 meter zeroing. After data entry, the rangefinder and scope are connected via Bluetooth. The illuminated reticle is switched on at the riflescope, then the Bluetooth LED in the magnification changer lights up for confirmation.

In the rangefinder, the serial number of the riflescope is shown in the display after the Bluetooth connection. This must be selected and saved. Both devices are now connected. The Bluetooth connection between the riflescope and the SIG Sauer Kilo 1800 BDX rangefinder is now automatically established after switching on. 

Operation and features of the SIG Sauer Kilo 1800 BDX

SIG Sauer rangefinder and scope
Some dealers also offer bundles consisting of SIG Sauer rangefinder and scope, usually at a slightly lower price.

When the top button of the SIG Sauer Kilo 1800 BDX rangefinder is pressed once, the device switches on and the red target mark becomes visible. A second press triggers the measurement. The display shows the distance, which can be set to either yards or meters. The settings are made using the mode button on the side. Only the top button is needed. The display also shows the battery status. Due to the Bluetooth connection, the device has a corresponding power consumption.

 the SIG Sauer Sierra3 BDX 4.5-14x44 riflescope
Due to the separate solution with external rangefinder, the SIG Sauer Sierra3 BDX 4.5-14x44 riflescope remains compact and lightweight.

If a range measurement is now carried out, the SIG Sauer Kilo 1800 BDX immediately transmits the calculated data to the riflescope. The corrected red aiming point moves on the reticle and takes into account shot distance, atmospheric influences, shot angle and the ballistics of all common calibers and loads at the touch of a button. The speed of the scan mode is impressive! It takes just a few milliseconds from scan to reticle adjustment. The ballistic computer detects the pitch angle, range and gives the correct ballistic distance to the scope. The display brightness adapts to the prevailing light conditions in a user-friendly manner.
Another interesting feature for hunters is the innovative "KinETHIC" function of the SIG Sauer BDX Electro-Optics. This indicates whether the ballistic performance at the targeted shooting range is sufficient to kill the game safely and in line with hunting requirements. If a fair game shot is not possible, the shooter is notified and should keep his finger straight.

According to the manufacturer, distances of up to 1800 meters can be measured under optimal conditions. I have been able to measure distances up to 1000 meters with the SIG Sauer Kilo 1800 BDX in the field. But that's because I can't hold the rangefinder steady enough in my hand to accurately detect objects at that distance. The laser rangefinder is encased in a magnesium housing, is waterproof, and is about the size of a pack of cigarettes weighing 220 grams. The eyecup of the SIG Sauer Kilo 1800 BDX can be screwed in for eyeglass wearers.

SIG Sauer Sierra3 BDX 4.5-14x44 riflescope in interaction

The compact mid-range SIG Sauer Sierra3 BDX 4.5-14x44 riflescope measures 12.6”/32 cm and weighs 24 oz/681 g. In good light conditions into twilight, the 44 millimeter objective lens diameter makes a good image. The image is sharp and contrasty, with edge-to-edge sharpness diminishing at high magnification.

The BDX-R1 reticle is located in the second image plane. The illuminated reticle control is on the left along with the parallax adjustment. The illuminated dot of the SIG Sauer Sierra3 BDX 4.5-14x44 can be dimmed in ten steps. Unfortunately, the illuminated dot is quite bright even at the lowest setting. However, this does not interfere with day hunting, for which the scope is mainly intended. There is a digital bubble level in the optic, which is displayed on the left and right side in the scope.

The SIG Sauer BDX system's approach of using the laser rangefinder separately as a device on its own, rather than integrating it directly into the scope as other manufacturers do, eliminates additional weight on the rifle. In some hunting situations, however, another person is needed to perform the range finding and provide the shooter's aiming system with the acquired data.

the BDX system from SIG Sauer
Fast setup and even faster use: with the BDX system from SIG Sauer, old-fashioned behaviors such as distance estimation or holding over become obsolete.

SIG Sauer Kilo 1800 BDX Rangefinder specs and price

SIG Sauer Kilo 1800 BDX
Laser Class:
Objective Lens Diameter: 
22 mm
Exit Pupil: 
3.6 mm
Response Time: 
0.25 seconds
Laser Divergence: 
1.3 MRAD
Up to 1800 m  
7.8 oz/221 g
4x1.3x 3 in (104 x 33 x 76 mm)
499 euro

SIG Sauer Sierra3 BDX 4.5-14x44 riflescope specs and price

SIG Sauer Sierra3 BDX 4.5-14x44
BDX-R1 Digital
1 click: 
.25 MOA
Exit Pupil: 
6.9-3.1 mm
Field of View: 
6.6-2.2 m (at 100 m)
Objective Lens Diameter: 
44 mm
Main Tube Diameter: 
30 mm
Overall Length: 
12.6”/320 mm
24 oz/681 g
809 euro

SIG Sauer Kilo 1800 BDX laser rangefinder with SIG Sauer Sierra3 BDX 4.5-14x44 riflescope: conclusion

SIG Sauer's BDX system is an affordable riflescope/rangefinder combo that delivers high performance for comparably little money and pushes the door open into the high-tech hunting arena. In this regard, the Sierra 3 BDX 4.5-14x44 is a high-quality, lightweight target optic that is also suitable for mountain and international hunting. Thanks to easily explained basic settings, the optics combo is quickly set up. In a split second, the reticle is then adjusted to the current situation with the push of a button on the SIG Sauer Kilo 1800 BDX rangefinder – taking hunting to a new level.

Andreas Jordt / Hunting Team North Schleswig

For more information on SIG Sauer's BDX system please visit the SIG Sauer website.

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Here at GSG you can buy the SIG Sauer Kilo 1800 BDX Rangefinder and SIG Sauer Sierra3 riflescopes:

SIG Sauer Kilo 1800 BDX Rangefind                     499 euro

SIG Sauer Sierra3 BDX 4.5-14x44                    809 euro

SIG Sauer Sierra3 BDX 4.5-14x50                 
899 euro

BDX-PACK Kilo 1800 Rangefinder + Sierra3 4,5-14x501.349 euro