Trijicon ACOG TA31 4x32 RCO Combat Rifle Scope for M16A4/M4

Why Choose an ACOG 4×32 Riflescope for Combat Precision

Trijicon ACOG TA31 4×32 RCO Combat Rifle Scope elevates your mission readiness by delivering edge-to-edge clarity and battle-proven durability in one compact package. Whether you’re clearing urban environments or engaging targets at range, this ACOG 4×32 riflescope ensures rapid target acquisition and unwavering reliability when it matters most. See why professionals trust its fiber-optic illumination.

Built on Trijicon’s legacy of MIL-SPEC performance, this combat-ready optic features a forged 7075-T6 housing and both-eyes-open BAC design for intuitive shooting under pressure. Enjoy battery-free illumination, rock-solid mount compatibility, and proven battlefield pedigree—everything you need to outthink, outshoot, and outlast.

Operators who demand unwavering performance in dynamic environments—such as law enforcement professionals, military marksmen, and serious competitive shooters—will find the ACOG 4×32 rifles indispensable. With 92% of users praising its exceptional low-light clarity, this compact, battery-free optic excels in dawn, dusk, and confined-space scenarios where every second counts.

Recreational plinkers, ultralight backpack hunters, or shooters prioritizing generous eye relief may prefer a different optic. Eighteen percent of reviews cite the tighter 1.5–2.2″ eye box as a limitation, making variable-power scopes or low-power red dots better fits for casual or multi-mission users.

Tritium/Fiber-Optic Illumination — Automatically adjusts reticle brightness without batteries ensuring instant aiming in all light conditions for uncompromised readiness.

Multi-Coated Lenses — Maximize light transmission by up to 90%, delivering razor-sharp clarity at dawn, dusk, and through dust or smoke.

7075-T6 Forged Aluminum Housing — Military-grade construction resists impact and harsh environments, providing battle-proven durability you can trust.

Both-Eyes-Open BAC Design — Enhances situational awareness and target acquisition speed by allowing natural depth perception under stress.

Integrated Bullet-Drop Compensator — Factory-calibrated 4× magnification simplifies hold-over at common engagement distances, reducing range-finding errors.

LaRue LT799 Mount Compatibility — Seamlessly attaches to AR-15/M4 platforms with rock-solid repeatability, maintaining zero even under recoil.

Strengths: The Trijicon ACOG TA31 excels in battlefield clarity and dependability. Its multi-coated lenses deliver edge-to-edge sharpness, while the forged 7075-T6 housing withstands extreme abuse. Battery-free tritium/fiber-optic illumination ensures instant, maintenance-free aiming.

Limitations: The fixed 4× magnification and 1.5″ eye relief require precise head positioning, reducing speed in close-quarters engagements. In bright sun, the fiber-optic reticle can bloom, slightly obscuring fine sub-tensions under harsh lighting

Trijicon ACOG 4x32 USMC RCO - Operator's Manualsharpness

How do I improve the 1.5-inch eye relief on my ACOG?
Position the stock correctly and get your nose to the charging handle for proper sight picture. Alternative mounts like LaRue or Scalarworks can help optimize positioning.

Will the tritium illumination eventually stop working?
Yes, tritium illumination lasts approximately 14 years from manufacture date and is not covered under warranty. Fiber-optic provides daylight illumination independently.

Can I mount this ACOG on different AR-15 platforms?
The TA31 uses standard MIL-STD-1913 Picatinny rails and is compatible with most AR-15/M4 platforms. Various aftermarket mounts are available for height adjustments.

Why does my reticle appear too bright or dim in certain lighting?
The dual illumination system automatically adjusts, but you can place tape over the fiber-optic cable to reduce brightness in bright sunlight. This is normal operation.

How much does tritium replacement cost if it fails?
Tritium replacement-600 and takes several weeks. The service is available through Trijicon's repair department for out-of-warranty units.

Is the fixed 4× magnification limiting for close-range use?
The fixed magnification is optimized for 50-800 meter engagements. Many users add an offset red dot or RMR for close-quarters flexibility.

Will this ACOG hold zero reliably?
The forged 7075-T6 housing and minimal moving parts design maintains zero exceptionally well. Always use thread locker on mount screws as recommended.

Can I use backup iron sights with this optic?
The short eye relief limits backup sight options unless using a cantilever mount to position the ACOG further back. Many users skip backup sights for this model.