There have been an avalanche of new optics on the market over the last decade; however, the legendary Trijicon Advanced Combat Optical Gunsight (ACOG) has remained one of the top choices for hard-use optics for many reasons. The major attractions for customers have been the military pedigree, bomb-proof durability, lightning-fast target acquisition, and the always-on dual illumination. Leveraging Trijicon’s Bindon Aiming Concept (BAC) feature and new BDC-equipped models, users can engage targets and maintain situational awareness with both eyes open while still having the flexibility to engage accurately at distance. The ACOG is an unique American-made optic which has continued to prove itself at its premium quality level and price point. For this review we are focusing on the most compact in the line, the Trijicon ACOG 1.5x16S model, which is about 30% smaller than the full-sized AGOCs and now offers BDC reticle options as well for 9mm and .223 Remington. There are many rifles we could have chosen to feature with the ACOG 1.5x16S but decided the new military trials and abuse-tested Caracal CAR816 short-stroke piston rifle is a fitting firearm for an optic with a military legacy.

The Little ACOG

The relatively small 1.5x16S is not necessarily new, but it has evolved since its introduction in 2010. In a world of continually shrinking optic footprints, the 4-inch overall length feels more substantial but the weight is lighter than expected. Compared to the standard 3.5 magnification ACOGs mounted to many military rifles, the 1.5x16S is half the length at 4 inches and a third the weight at only 7.2 ounces, including the Q-LOC mount. It is sized similar to larger holographic sights but delivers more clarity plus magnification. The new RTR Bullet Drop Compensating reticle options for .223 and 9mm carbine are expected to be attractive options for allowing accurate shots to 700 yards with 55-grain .223 rounds and to 300 yards with the 9mm PCC-calibrated reticle. Also included with the BDC hashmarks are wind hold distances. In my testing, I found the .223 BDC reticle holds to be very close to perfect to 500 yards with 16-inch-barreled CAR816 with typical mil-spec velocity 55-grain rounds. 

Like all ACOG optics, the small format still retains the durability of the rugged forged 7075-T6 aircraft-grade aluminum chassis and minimal moving parts design, resulting in a sighting system that is nearly indestructible. ACOGs also have highly simplified use thanks to the fixed power, which means the shooter is always on the right and expected magnification instead of fumbling for the right magnification setting. The optics are meticulously crafted with high-quality glass and multi-coated lenses to maximize light-gathering capabilities and provide a clear, distortion-free field of view. Optic coatings have advanced over the years to improve clarity, durability and help shed water and dirt. Waterproof performance is exceptional, exceeding military standards, and all scopes are dry nitrogen-filled to prevent fogging, allowing it to perform flawlessly in extreme cold and heat. 

Though Trijicon makes extremely clear optics, the unique feature is the no-battery-required dual-illumination fiber optic and tritium-phosphor light sources. Most models are available in green, yellow or red illumination options. For those who want an absolutely maintenance-free optic, free from the need of batteries, the ACOGs with etched reticles and dual non-electrical illumination are very attractive. The sealed fiber optic external pipe pulls in ambient light to illuminate the center dot, and in total darkness, the tritium illumination takes over, delivering a visible center dot. There has been much debate lately as to the relevance and required expense of this type of illumination with LED and ultra-long running 50K hours + red-dot optics; however, the military and many civilian customers obviously feel that reliance on battery power and electro-optics in extreme situations has a downside. To date, the ACOG still leads the industry when it comes to nearly bomb-proof power-free illuminated optics.

The most significant updates to the Trijicon ACOG 1.5x16S scope has been the mount. The Q-LOC Technology mount is simple and a highly durable quick release mount that can be easily attached or removed tool-free with the oversized thumb screw. Trjicon noted that the Q-LOC Mil-Spec drop-test-rated 6061-T6 aluminum mount is designed to retain better than 1-MOA zero when removed and remounted; however, most customers experience no shift in point of impact when mounted to the same rail slot and torque. Its user-friendly, one-handed, toolless, spring-loaded mounting system ensures quick and secure installation and has been designed to retain zero and deliver a constant retention, even if the knobs are not tightened.

Windage and elevation adjustments can be made effortlessly without the need for tools, thanks to the ACOG’s lanyard capped external adjusters. The 1.5x16 model offers a larger field of view (7.4 degrees) and an extremely wide eye box, enabling easier and faster target acquisition even with imperfect shoulder mounts or in awkward positions. This small-format ACOG has a lot that will be attractive for customers just based on features. Within the firearms industry, optics are almost always made overseas, so Trijicon’s made in USA optics are a unique selling point that is often overlooked by sellers.             

Trijicon 1.5x16S Specifications

Finish: Matte black anodized

Made: USA

Torque: Spring tension only: 12-16 in. / lbs.

can be tightened to 44-66 in. / lbs.

Length x Width x Height: 4 in x 2.10 in x 2.58 in

Weight: 7.2 oz. (204.12g)

Magnification: 1.5x

Objective Size: 16mm

Reticle Pattern: Rapid Target RTR

Day Reticle Color: Red

Night Reticle Color: Red

Bullet Drop Compensating (BDC): Yes

Caliber: .223 Rem / 55 gr

Bindon Aiming Concept (BAC): Yes

Illumination Source: Fiber Optics & Tritium

Power Source: Fiber Optics & Tritium

Adjustment: 2 clicks per in. @ 100 yards

Eye Relief: 2.4 in. (60.96mm)

Exit Pupil: 0.42 in. (10.67mm)

Field of View (degrees): 7.4°

Field of View (feet): 39 ft. @ 100 yds (13m @ 100m)

Mount: Trijicon Q-LOCTM Technology Mount

Housing Material: Forged Aluminum