SIG SAUER SIERRA6BDX 5-30x56mm BDX-R2 Riflescope

The SIG SAUER SIERRA6BDX 5-30x56mm is a high-magnification riflescope built around SIG’s Ballistic Data Xchange platform. This exact model, identified by MPN SOSBDX65111, combines a broad 5-30x magnification range, a large 56mm objective, a 34mm main tube, and the BDX-R2 digital ballistic reticle in a black second-focal-plane configuration. It is intended for shooters who want conventional precision-scope controls together with the option to integrate compatible SIG BDX rangefinding and ballistic data.

5-30x magnification range

At 5x, the scope retains enough field of view for observation and target acquisition at moderate distances. Moving toward 30x provides the image scale needed for precise aiming, target inspection, and shot placement at extended range. The 56mm objective supports the high-magnification format by gathering light through a large front lens, while the 34mm tube provides the body size used by this exact SIERRA6BDX configuration.

The reticle is located in the second focal plane, so its apparent size remains constant as magnification changes. That gives the shooter a consistent-looking aiming pattern throughout the zoom range. As with any second-focal-plane optic, review SIG SAUER’s instructions for the magnification settings and procedures used with reticle references and ballistic functions.

BDX-R2 digital ballistic reticle

The BDX-R2 is a digital ballistic reticle designed to work within SIG’s BDX ecosystem. When the scope is paired with compatible BDX equipment and properly configured, the system can communicate range and ballistic information to provide an illuminated aiming reference. SIG describes compatible SIERRA6 scopes as capable of pairing with a BDX-equipped rangefinder to bring Applied Ballistics capability into the field without requiring a mobile device for every range engagement.

Correct results depend on accurate ballistic data, firearm zero, environmental inputs, equipment pairing, and user setup. The digital system supplements rather than replaces proper zero confirmation, sound range estimation, and verification at known distances. Follow the optic, rangefinder, and BDX application instructions before relying on a calculated hold.

Precision adjustments and parallax control

This model uses 0.25 MOA adjustments, allowing measured corrections to windage and elevation. Its adjustable parallax system helps the shooter refine focus and reduce apparent reticle movement at varying distances. Eye relief is listed from approximately 3.70 to 3.90 inches, providing a useful setup range when positioning the scope on a compatible rifle.

SIG’s SpectraCoat lens coating is specified for this variant. The coating is intended to support light transmission and image clarity through the optic’s magnification range. Final optical performance also depends on ambient conditions, correct diopter adjustment, clean lenses, and a stable mounting system.

Key specifications

• Manufacturer: SIG SAUER
• Model: SIERRA6BDX
• Manufacturer part number: SOSBDX65111
• UPC: 798681628018
• Magnification: 5-30x
• Objective diameter: 56mm
• Main tube: 34mm
• Focal plane: Second focal plane
• Reticle: BDX-R2 digital ballistic reticle
• Adjustment value: 0.25 MOA
• Parallax: Adjustable
• Eye relief: Approximately 3.70-3.90 inches
• Lens coating: SpectraCoat
• Finish: Black

Matching the optic to the rifle

The 5-30×56 model is best evaluated as a precision-oriented optic. Its 56mm objective and 34mm tube require appropriate ring height, clearance over the barrel, and sufficient mounting space on the receiver. The rifle’s balance and intended firing positions should also be considered because large-objective, high-magnification optics can affect handling. Before final installation, check bolt-handle clearance, maintain adequate eye relief at every magnification, and confirm that the reticle is level with the rifle. A stable mount and repeatable cheek position are essential for taking advantage of the scope’s adjustment range and digital ballistic functions.

Before mounting

Verify that your rings are the correct diameter for a 34mm tube and that the mounting system is suitable for the rifle and cartridge. Follow the mount and optic manufacturers’ torque specifications, establish a mechanical zero, and confirm point of impact at the range. Compare the MPN and UPC before ordering because the SIERRA6BDX family includes several magnification, objective, tube, and reticle combinations that are not the same product.