Sig Sauer Electro-Optics SOSBDX4411 Sierra4 BDX Black 4-16x44mm 30mm Tube Illuminated BDX-R2 Ballistoc w/194 LEDS Reticle

The Sig Sauer Sierra4 BDX is a 4-16x44mm rifle scope built for hunters and long-range shooters who want ballistic calculation and environmental data fed directly into their optic. This isn't just a scope with a reticle—it's a connected system. Pair it with a Sig BDX-equipped rangefinder, and the scope receives real-time ballistic solutions that account for distance, wind, temperature, and spin drift, displaying an exact holdover dot on the digital focal plane. The result is faster, more confident shots at distance without manual math or guesswork.

The scope's 194 individually controlled LEDs form the BDX-R2 digital reticle, which lives on a digital focal plane rather than etched glass. That means the reticle and the target stay locked together at a precise scale, eliminating the parallax error that plagues traditional reticles and improving accuracy further. You can also run SmartBDC mode to choose from nine onboard ballistic groups or load a custom profile if you prefer to shoot without a rangefinder. The 30mm main tube delivers rugged, waterproof (IPX7) construction, and the optical system transmits up to 95% of available light for a bright, clear sight picture across the 4x to 16x magnification range. Bluetooth connectivity reaches up to 30 yards—useful for shooter-spotter pairs who need to stay in sync across broken terrain.

At 4-16x magnification with a 44mm objective, this scope covers everything from mid-range hunting to precision rifle work. The eye relief spans 2.44 to 3.24 inches, and the field of view runs from 3.33 feet at 100 yards on low magnification to 1.25 feet on high. Total elevation and windage travel both exceed 70 MOA, and each rotation of the turrets adjusts point of aim by 25 MOA. Two CR2032 batteries power the digital reticle. No mount is included, so plan on sourcing a 30mm scope ring separately.

If you're already invested in the Sig BDX rangefinder ecosystem, the Sierra4 BDX closes the loop between distance measurement and ballistic solution. If not, the scope still functions as a premium variable-power optic with onboard ballistic profiles and a bright digital reticle—and the system is there if you ever decide to add a rangefinder down the road.

Key Features

• BDX Ballistic Data Xchange Technology—pairs with Sig BDX rangefinders to calculate and display exact holdover solutions using real-time ballistic and environmental data
• BDX-R2 digital reticle with 194 individually controlled LEDs on a digital focal plane for precision aiming and zero parallax error
• SmartBDC onboard ballistics—choose from 9 factory ballistic groups or customize a profile for your rifle and ammunition
• 30mm main tube with waterproof (IPX7) construction and up to 95% light transmission for durability and optical clarity
• Bluetooth connectivity up to 30 yards for seamless communication with compatible rangefinders
• 4-16x magnification with 44mm objective lens—versatile for hunting and precision shooting
• Two CR2032 batteries power the digital reticle

Specifications

Frequently Asked Questions

Will the Sierra4 BDX work without a Sig BDX rangefinder?

Yes. The scope includes SmartBDC onboard ballistics—you can select from nine factory ballistic groups or build a custom ballistic profile loaded into the scope itself. The BDX rangefinder connectivity adds convenience and real-time environmental corrections, but it's not required to use the scope. You can dial and aim manually just like any high-quality rifle scope.

What rangefinders are compatible with this scope?

The scope pairs with Sig Sauer's BDX-equipped rangefinders via Bluetooth. For a specific model list, confirm compatibility with Sig's product documentation or contact our team, as new rangefinder models may be released.

Does this scope come with rings or a mount?

No. The scope has a 30mm main tube and requires a separate 30mm scope ring or mount. Make sure your mount and rings are rated for 30mm tubes.

What's the battery life on the digital reticle?

The scope runs on two CR2032 batteries. For estimated runtime and battery-life information under typical field use, consult Sig Sauer's product literature or user manual.