SIG SAUER SIERRA3BDX Riflescope
- Magnification Minimum: 4.5x
- Magnification Maximum: 14x
- Objective Lens Diameter: 50 mm
- Mounting Type: Cantilever Mount
Last refreshed Jun 22, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
This scope earns its keep only within SIG's BDX ecosystem, but for hunters who own a compatible rangefinder it delivers on the automatic holdover promise, calibration issues aside.
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ASIN: B07DWZV326Model: SIERRA3BDXCategory: Rifle Scopes
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Overview
A 30mm riflescope built around SIG's BDX Ballistic Data Xchange system, pairing over Bluetooth with a BDX rangefinder to display an automatic holdover dot scaled to the shooter's zoom level and ballistic profile.
The scope's core feature is software, not glass: paired with a KILO series BDX rangefinder, it ranges a target and lights an OLED dot at the calculated holdover point instead of asking the shooter to hold over by eye. Auto LevelPlex adds cant sensitivity as the shot gets longer, and KinETHIC flags when energy on target drops below a hunter-set threshold.
- Second Focal Plane with OLED illuminated holdover dot
- Auto LevelPlex cant sensitivity on longer shots
- KinETHIC kinetic energy threshold indicator
- IPX-7 waterproof rated for full immersion to 1 meter
Who it's for
Hunters and long range shooters who already own or plan to buy a compatible SIG BDX rangefinder, and who want automated holdover rather than dialing turrets. Less suited to shooters who want a simple optic with no app or pairing step.
Pros and cons
- Automatic holdover dot removes manual ballistic dialing
- Bullet profiles save per rifle across multiple guns
- IPX-7 waterproof and fogproof for all-weather hunting
- Some units arrive with Auto LevelPlex out of calibration
- Crosshairs are wider than a dedicated target scope reticle
- Requires a compatible BDX rangefinder and app setup
Specifications
| Brand | Sig Sauer |
|---|---|
| Model | SIERRA3BDX |
| Dimensions & fit | |
| Objective Lens Diameter | 50 mmhigher than 69% of 309 rifle scopes |
| Construction & materials | |
| Material Type | Plastic |
| Color | Black |
| Compatibility & installation | |
| Mounting Type | Cantilever Mount |
| Compatible Devices | Rifle |
| Included components | |
| Unit Count | 1 |
| Warranty & support | |
| Warranty Description | 2 years |
| Other details | |
| Magnification Minimum | 4.5x |
| Magnification Maximum | 14x |
| Night vision | No |
| Thread Type | 30mm |
| Sport Type | Airsoft |
| Reticle Type | BDX R1 Digital |
| Field Of View | 19.9 feet |
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Frequently asked questions
Does the SIERRA3BDX work without a SIG rangefinder?
It functions as a standard riflescope on its own, but the automatic holdover dot that defines the BDX system requires pairing with a compatible SIG BDX rangefinder over Bluetooth.
Is the scope waterproof?
It carries an IPX-7 rating for complete immersion up to 1 meter and is built fogproof.