Trijicon ACOG TA31-D 4x32 Green Horseshoe Scope
- Magnification Minimum: 4x
- Objective Lens Diameter: 32 mm
- Mounting Type: Picatinny Mount
- Night vision: No
Last refreshed Jun 22, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A durable, battery-free 4x combat optic with a clear reticle, the eye relief takes some adjustment but owners who have run several ACOGs keep coming back to the line.
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ASIN: B00IBHY2JYModel: ACOG TA31-D-100367Category: Rifle Scopes
More from this brandAll Trijicon rifle scopesOverview
This is a Trijicon ACOG 4x32 rifle scope with a green horseshoe dot BAC reticle, calibrated for 5.56/.223 flattop rifles out to 800 meters. It comes in the Dark Earth finish with a forged aluminum housing.
The reticle uses dual illumination, fiber optics for daylight and tritium for low light, so it needs no battery to stay lit. It ships with a flattop adapter and lanyard assembly for the adjuster caps.
- 4x magnification, 32mm objective lens
- Green horseshoe dot BDC reticle, dual illuminated
- Bullet drop compensation to 800 meters
- Dark Earth finish, forged aluminum housing
Who it's for
AR-pattern rifle owners who want a rugged, battery-free combat optic and are prepared to adapt to a tighter eye relief than a typical variable scope. Less suited to shooters who prioritize a wide, forgiving eye box.
Pros and cons
- No battery required, illuminates via fiber optics and tritium
- Reticle calibrated for 5.56/.223 out to 800 meters
- Forged aluminum housing described as rugged by repeat owners
- Can be paired with an RMR on a mounting plate for close-quarter use
- Eye relief is tight compared to many other rifle scopes
- High price point for the magnification level offered
Performance notes
Illumination comes from fiber optics in daylight and tritium at night, so the reticle stays lit without a battery or switch to manage. The BDC reticle is calibrated out to 800 meters for 5.56/.223 loads on flattop rifles.
Specifications
| Brand | Trijicon |
|---|---|
| Model | ACOG TA31-D-100367 |
| Dimensions & fit | |
| Objective Lens Diameter | 32 mm |
| Item Weight | 2 pounds |
| Construction & materials | |
| Material Type | Polymer |
| Compatibility & installation | |
| Mounting Type | Picatinny Mount |
| Compatible Devices | Rifle |
| Included components | |
| Unit Count | 0.06 pounds |
| Other details | |
| Magnification Minimum | 4x |
| Night vision | No |
| Thread Type | UNC |
| Sport Type | Hunting, Target Shooting |
| Field Of View | 36.8 feet |
Frequently asked questions
Does the Trijicon ACOG TA31-D-100367 need batteries?
No, the reticle is illuminated by fiber optics during the day and tritium at night, so it works without a battery.
What caliber is the reticle calibrated for?
The BAC reticle is calibrated for 5.56/.223 flattop rifles, with bullet drop compensation out to 800 meters.