First Look: SIG Sauer Sierra4-BDX Rifle Scopes

Automatically shows your holdovers when used with a KiloBDX rangefinder.

by
posted on August 22, 2025
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SIG Sauer Sierra4-BDX

The new Sierra4-BDX is SIG Sauer’s most advanced BDX enabled riflescope yet. The scope pairs seamlessly with SIG’s line of Kilo BDX rangefinders and create a precise holdover dot based on your ballistic performance of your cartridge, environmental conditions and distance to the target.

The Sierra4-BDX riflescope simplifies shooting at distance by connecting to BDX-equipped rangefinders to deliver an illuminated holdover dot specific to your target distance, ballistic performance and other factors like the wind and weather. With a digital focal plane and 194 LED hold points, Sierra4-BDX scopes make it easy to make the shot when it matters the most.

Sierra4-BDX Features:

  • BDX Ballistic Data Xchange Technology: Pairs with KiloBDX rangefinders to calculate and display an exact holdover dot using real-time ballistic and environmental data.
  • BDX-R2 Digital Reticle: 194 individually controlled LEDs on a digital focal plane for hyper-precise aiming.
  • SmartBDC Technology: Choose from 9 onboard ballistic groups or customize your setup for total control.
  • Advanced Bluetooth Antennae: Improved connectivity up to 30 yards, an important feature for shooter-spotter pairs when terrain dictates your position.
  • Rugged Performance: Waterproof (IPX7), 30mm main tube and high-grade optical system with up to 95 percent light transmission.

Sierra4-BDX 4-16x44mm Second Focal Plane (SFP) Specifications

  • Magnification: 4-16X
  • Objective Lens Diameter: 44 mm
  • Weight : 22.7 ounces
  • Main Tube Diameter: 30mm
  • Total Elevation Travel: 70 MOA+

Sierra4-BDX 6-24x50mm Second Focal Plane (SFP) Specifications

  • Magnification: 6-24X
  • Objective Lens Diameter: 50mm
  • Weight : 24.4 ounces
  • Main Tube Diameter: 30mm
  • Total Elevation Travel: 48 MOA+

MSRP for the Sierra4-BDX 4-16x44mm is $699.99, and the MSRP for the Sierra4-BDX 6-24x50mm is $799.99. More information on these new optics, the KiloBDX line of rangefinders and other firearms, accessories and optical products made by SIG Sauer is available at sigsauer.com.

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