SIG SAUER SIERRA6BDX 2-12x40mm BDX-R2 Riflescope

The SIG SAUER SIERRA6BDX 2-12x40mm combines a versatile magnification range with SIG’s Ballistic Data Xchange technology. Cataloged under MPN SOSBDX62111, this exact scope uses a 30mm main tube, 40mm objective, second-focal-plane BDX-R2 digital ballistic reticle, and 0.25 MOA adjustments. Its 2-12x range is broad enough to support close-to-intermediate observation at the low end while providing additional detail and aiming precision as distance increases.

Versatile 2-12x optical range

Starting at 2x makes this SIERRA6BDX useful when a wide field of view and quick target acquisition are priorities. Increasing magnification toward 12x provides a closer view for smaller targets, more deliberate shot placement, and field observation at longer distances. The 40mm objective keeps the optic comparatively streamlined while supporting the light-gathering needs of the 12x top end.

The reticle remains the same apparent size throughout the magnification range because it is positioned in the second focal plane. This gives the shooter a consistent visual reference while zooming. Users should follow SIG SAUER’s guidance for the correct magnification settings and procedures when applying reticle references or digital ballistic solutions.

BDX-R2 digital ballistic capability

The BDX-R2 reticle is designed for integration with SIG’s BDX system. When paired with compatible BDX rangefinding equipment and configured with accurate ballistic information, the system can communicate a calculated solution to the scope and present an illuminated aiming reference. SIG describes the SIERRA6 platform as able to pair with a BDX-equipped rangefinder so Applied Ballistics capability can be brought into the field without requiring a mobile device for each individual range engagement.

Ballistic technology is only as reliable as its inputs and setup. Confirm the rifle’s actual zero, ammunition performance, sight height, and environmental information, then verify calculated holds on a controlled range. The BDX system should complement—not replace—fundamental marksmanship, safe target identification, and knowledge of the firearm’s trajectory.

Adjustments, focus, and lens treatment

This scope provides 0.25 MOA windage and elevation adjustments for measured point-of-impact correction. The product specifications list parallax at 100 yards for this configuration. Eye relief is approximately 3.70 to 3.90 inches, giving the installer room to establish a safe and repeatable head position on the rifle.

SpectraCoat lens treatment is specified to support light transmission and image clarity. Proper performance still depends on careful mounting, diopter setup, clean lenses, and a stable shooting position. The 30mm tube requires compatible 30mm rings or a mount designed for the rifle platform.

Key specifications

• Manufacturer: SIG SAUER
• Model: SIERRA6BDX
• Manufacturer part number: SOSBDX62111
• UPC: 798681627998
• Magnification: 2-12x
• Objective diameter: 40mm
• Main tube: 30mm
• Focal plane: Second focal plane
• Reticle: BDX-R2 digital ballistic reticle
• Adjustment value: 0.25 MOA
• Parallax setting: 100 yards
• Eye relief: Approximately 3.70-3.90 inches
• Lens coating: SpectraCoat
• Finish: Black

Practical setup considerations

The 2-12×40 configuration suits rifles that need more flexibility than a dedicated high-magnification optic. Its lower starting power can support closer field observation, while 12x provides useful detail for deliberate shots at greater distance. When selecting rings, account for the 30mm tube, objective clearance, receiver geometry, and a comfortable cheek weld. Establish eye relief at the highest magnification before tightening the mount because that setting typically provides the least forgiving eye box. After installation, level the reticle, confirm all fasteners to the mount manufacturer’s specification, and verify zero with the exact ammunition intended for use.

Confirm the exact scope

The SIERRA6BDX line includes multiple power ranges, objective sizes, tube diameters, and reticle configurations. Confirm both SOSBDX62111 and UPC 798681627998 before ordering. Use only a compatible mounting system, follow the manufacturer’s torque specifications, and verify zero after installation. Review the SIG SAUER optic and BDX documentation before pairing devices or configuring ballistic profiles.