The Ultimate Firearms Destination for the Gun Lifestyle


At RECOIL, we review every product fairly and without bias. Making a purchase through one of our links may earn us a small commission, and helps support independent gun reviews. Learn More


This is the first of the RECOIL ICONIC Series. These shorts highlight, celebrate, and discuss guns, gear, and accessories that have stood the test of time and are emblematic of entire categories — those that represent a paradigm shift and influence all those that follow.

This article is about magnified combat optics, specifically the Trijicon ACOG (Advanced Combat Optical Gunsight). There isn’t a magnified optic in the history of the world that has seen more combat use, ever, than the ACOG.

First launched in 1987 with the TA01 model, these tritium-illuminated prismatic sights eventually changed the face of modern warfare. Used in small numbers since their inception, their first major contract was with SOCOM in 1995 for the TA01NSN.

TA01 models trickled down to regular joes, and the Marine Corps noticed. An updated variation featuring the addition of fiber optic illumination as well as a red chevron reticle with a bullet-drop compensator, called the TA31F, was deployed in smaller numbers in 2004, quickly followed by the Marines’ own version, the TA31RCO. More than 100,000 TA31RCOs ended up serving atop M16A4s, M4A1s, and M27 IARs in every locale the Marine Corps put boots down.

Trijicon included an integral scope mount that doesn’t require leveling or other fussing about, so it’s stupid simple to install. The fiber optic illuminates the center chevron during the day with self-luminous tritium for nighttime, so there’s no batteries to worry about.

To excel as a general-purpose combat optic, it must increase individual solder lethality, be versatile, be easy to use, and be hard to break.

Real life isn’t Call of Duty with a gear-selection screen; outside of extremely special units, you roll with what you’re issued. As the U.S. Military requires the ability to be competent in any operational environment in the world, any mass-issue combat optic needs to be adaptable for every situation within the range of the weapon it’s mounted on. 


Every American evolution of warfighting since the advent of the rifled barrel has been biased toward increasing individual soldier lethality, granting larger potential envelopes of engagement, and increasing operational independence. 

In fact, ACOGs plussed up individual lethality so much that some USMC units after Operation Phantom Fury in 2004 were investigated under suspicion of executing prisoners — because there were so many headshots taken at range. While every war has its war criminals, all these investigations proved was the utterly lethal effectiveness of the ACOG from house-to-house and rooftop-to-rooftop. 


The ACOG is so versatile not because it’s exceptional at any single thing, but because it’s pretty OK at everything. It’s workable at close range, excels at medium range, and gives you a better chance at long range than anything outside of a variable optic. 

The first approach at improving CQB performance happened in 1992 and was dubbed the Bindon Aiming Concept (BAC), after the creator Glyn Bindon. With this technique, you keep both eyes open with one looking through the optic and the other directly at the target, and your brain will superimpose the reticle on your non-dominant eye.

iRay Micro RH25
Here the iRay RH25 is in clip-on mode in front of a Trijicon ACOG, mounted on a Hodge Defense 12.5-inch carbine with a Dead Air Nomad-TI silencer.

The effectiveness of running occluded depends not only on training but also relative eye dominance and the physical shape of your eyes. Needless to say, BAC can work in a pinch but isn’t the best solution. 

To make up for the limitations at short range, unconventional position shooting, and use with night vision, some began running 1x reflex dot sights in-conjunction. Shortly after ACOGs began being purchased in large quantity by the DoD, these piggyback dot options became common accessories. In fact, the Trijicon RMR was specifically designed and developed for use with an ACOG — to replace the fragile 1x dots, not to ride the pistol on your hip.

Virtually every form of offset sight is common to see with an ACOG, and these enhancements were also applied to LPVOs and other magnified optics.


While the U.S. military is the most educated and experienced fighting force the world has seen to date, not everyone is a Rhodes Scholar nor capable of quick math, let alone scribbled ballistic calculations. 

An integral bullet-drop compensator (BDC) simply means there are holdover stadia marks on the reticle itself for targets at various ranges. Physics and ballistics being what they are, a BDC is only accurate for a given caliber, projectile weight, and velocity (barrel length). As an individual choice, a BDC doesn’t make a ton of sense because it limits options, but for an organization that uses weapons and ammunition within those given confines, it greatly reduces the learning curve.

The ACOG features a reticle with a bullet drop compensator — the numbered stadia marks represent the approximate holdover for targets at those ranges (such as 400 or 600 yards).

Simply use the chevron for everything between zero and 300 meters and make a guestimate on the BDC stick thereafter. After zeroing, there are no knobs to turn, batteries to swallow, or switches to forget.


The fixed prism optical elements of the ACOG add to both the simplicity and toughness. And, damn, they’re durable. So durable, in fact, that the Marine Corps discovered ACOGs have a lower failure rate than iron sights. Nuff said.


Despite the design rapidly approaching 40 years, the ACOG still remains a viable choice as a general-use combat optic to this very day. There’s better out there — but f*cking beware the one on the roof with an ACOG.  

Enter Your E-Mail to Receieve a Free 50-Target Pack from RECOIL!

NEXT STEP: Download Your Free Target Pack from RECOIL

For years, RECOIL magazine has treated its readers to a full-size (sometimes full color!) shooting target tucked into each big issue. Now we've compiled over 50 of our most popular targets into this one digital PDF download. From handgun drills to AR-15 practice, these 50+ targets have you covered. Print off as many as you like (ammo not included).

Get your pack of 50 Print-at-Home targets when you subscribe to the RECOIL email newsletter. We'll send you weekly updates on guns, gear, industry news, and special offers from leading manufacturers - your guide to the firearms lifestyle.

You want this. Trust Us.

Add a comment

Your email address will not be published. Required fields are marked *

Subscribe to the Free