Trijicon ACOG 4x32 Rifle Scope with RCR Red Dot Sight – TA31-C-100813

The Trijicon ACOG 4x32 Rifle Scope with RCR Red Dot Sight (SKU TA31-C-100813) is a factory two-optic package: a fixed 4x magnification, 32 mm objective ACOG prism rifle scope with an etched BAC .223 bullet drop compensating reticle calibrated for .223/5.56 and battery-free fibre-optic and tritium illumination, paired with a Trijicon RCR enclosed-emitter red dot sight with a 3.25 MOA dot, supplied with its ACOG-top mount.

The pairing solves the one thing a fixed-power ACOG cannot do on its own. The ACOG gives you 4x magnification and a calibrated bullet drop reticle for identification and holds at distance; roll the rifle onto its side and the RCR gives you a 1x red dot for anything close and fast. Neither optic depends on the other: the ACOG reticle is etched into the prism and lit by fibre optic and tritium with no battery, and the RCR runs its own LED from a CR2032 cell.

Why the RCR rather than an RMR: the RCR is Trijicon's enclosed-emitter design, so the emitter and the lens sit inside a sealed housing rather than facing the weather across an open bridge. Mud, rain and snow have no open path to the emitter, which is the failure mode that catches out open-emitter dots on a wet range day.

Trijicon designed the ACOG — Advanced Combat Optical Gunsight — for military service. That heritage is engineering, not marketing: a forged aluminium housing, a waterproof seal, an etched reticle that cannot fail, and a magnified sight that has nothing to switch on.

How It Compares

If you would rather have Trijicon's open-emitter RMR on top, the same ACOG 4x32 is packaged that way in four reticle and illumination combinations — the ACOG 4x32 Chevron Red reticle with RMR red dot sight (TA31-D-100549), the ACOG 4x32 Chevron Green reticle with RMR (TA31-D-100548), the ACOG 4x32 Crosshair Red reticle with RMR (TA31-C-100550) and the ACOG 4x32 Crosshair Green reticle with RMR (TA31-C-100552). For the ACOG on its own, choose your reticle from the ACOG 4x32 Chevron rifle scope, the ACOG 4x32 Crosshair rifle scope or the ACOG 4x32 Horseshoe/Dot rifle scope. The RCR is also sold on its own as the Trijicon RCR enclosed red dot sight (RCR1-C-3300001). See the whole range in Trijicon ACOG rifle scopes, the optics for straight-pull rifles, the wider offset and secondary red dot sights and the full Trijicon optics range, or read our enclosed versus open red dot guide and Trijicon buyer's guide.

Ideal For

• Civilian Service Rifle and practical rifle shooting where one stage mixes close targets with 200 m and 300 m detail
• Practical shotgun, 3-Gun and multi-discipline straight-pull carbine shooting, rolling from magnified to 1x without changing optics
• Wet British range days and winter shoots, where an enclosed emitter has no open path for rain or mud
• Shooters who want the magnified sight to keep working whether or not any battery does

Key Features

• ACOG Reticle: BAC .223 reticle — etched into the prism, calibrated for .223/5.56
• ACOG Illumination: Fibre optic and tritium, battery-free — daylight feeds the fibre and tritium lights the reticle in darkness
• Secondary Sight: Trijicon RCR enclosed-emitter red dot sight, 3.25 MOA dot, supplied with an ACOG-top mount
• Magnification / Objective: 4x magnification, 32 mm objective on the ACOG; 1x on the RCR
• Aiming Concept: Bindon Aiming Concept (BAC) for both-eyes-open shooting at magnification
• Eye Relief: 1.5 in (38 mm) on the ACOG
• Power: One CR2032 coin cell for the RCR; the ACOG needs no battery
• Housing: Forged aluminium, waterproof
• Origin: Made in USA

Technical Specifications

What's Included

• Trijicon ACOG 4x32 rifle scope (TA31-C-100813)
• Trijicon RCR enclosed red dot sight
• ACOG-top mount for the RCR
• Lens covers
• CR2032 battery
• User manual
• Warranty documentation

Warranty

Covered by Trijicon's manufacturer's warranty. Keep your order confirmation as proof of purchase and register the optic with Trijicon after fitting; we handle warranty claims for you from the UK.

UK Delivery & Support

UK-stocked and dispatched tracked from our UK warehouse — no import duties or customs delays — backed by UK-based support and Trijicon's warranty.

Frequently Asked Questions

Does the Trijicon ACOG 4x32 need batteries?
No — the ACOG half of this package is battery-free. A fibre-optic light pipe along the top of the housing collects ambient daylight and feeds it into the etched reticle, and a sealed tritium lamp illuminates the same reticle in darkness. The RCR red dot mounted above it is a separate sight powered by one CR2032 coin cell, so the magnified optic keeps working regardless of the dot.

What is the Bindon Aiming Concept (BAC) on a Trijicon ACOG?
The Bindon Aiming Concept (BAC) is Trijicon’s name for shooting an illuminated ACOG with both eyes open. The reticle is bright enough that the brain favours the magnified sighting eye for the aiming point while still using the unmagnified view from the other eye, so you keep close-range speed and situational awareness at 4x magnification.

Which calibre is this ACOG reticle calibrated for — .223 or .308?
This Trijicon ACOG 4x32 (TA31-C-100813) is calibrated for .223/5.56: the bullet drop compensating stadia below the aiming point correspond to that cartridge. Trijicon calibrates the ACOG for .308/7.62 in the larger 3.5x35 body instead — see the Trijicon ACOG rifle scopes collection.

What is the difference between the RCR and the RMR on top of an ACOG?
The Trijicon RCR is an enclosed-emitter red dot sight, so its emitter and lens are sealed inside the housing, while the Trijicon RMR is an open-emitter design with the emitter exposed across an open bridge. Both are 1x sights that piggyback above the ACOG; the RCR is the one to choose if the optic will live outdoors in British weather.

What is the eye relief on the Trijicon ACOG 4x32?
The Trijicon ACOG 4x32 has 1.5 in (38 mm) of eye relief. That is short by rifle scope standards and typical of a compact prism optic, so it wants a consistent cheek weld and a mounting position that puts your eye close to the ocular.

What happens to the aiming point if the ACOG illumination is not visible?
The ACOG reticle is etched into the prism glass rather than projected, so the full aiming point and its bullet drop stadia remain black and usable against a bright background even when the tritium and fibre-optic illumination is not contributing.