One of the finest series combat rifle scopes made is the Trijicon ACOG telescopic sights. ACOG is an acronym for Advanced Combat Optical Gunsight. The ACOG series is actually two different sight lines. First there is the original full sized ACOG and recently Trijicon has added the Compact ACOG series expanding the line out to cover nearly any choice of magnification, reticle and size.

The ACOG comes in five models: 4x32, 3.5x35, 3x24, 2x20, and 1.5x16. There are six different reticles including dot, doughnut, triangle, crosshairs, ranging crosshairs and a second smaller triangle. There are two  mounting options: AR-15/M-16 carry handle or a special ring mounting. There are a variety of mounts from Trijicon and ARMS to adapt the AR-15/M-16 mount to most other rifles. Most reticles come in red or amber and all models come with an optional Bindon Aiming Concept (BAC). Quoting from Trijicon “The BAC is an ... optical breakthrough that combines traditional long-stand-off marksmanship capability with the ultimate in close-combat transitional aiming. Using the two-eye aiming method, when the weapon is being moved, the perceived image is unmagnified, permitting extremely rapid target acquisition. As soon as the weapon movement is stopped and the shooter is close to the proper aim on target, the targeted image “zooms” into magnification, permitting greater shooting accuracy with higher hit ratios”. The BAC models have a fluorescent fiber light-gathering tube that is exposed across the top of the scope. The Compact ACOGs are about half the size and weight of the original 4x32 model.

After weighing though the many options I ended up purchasing the $456 TA50-4 which equates to a 3x24 Compact ACOG with M16 base, amber crosshair and the Bindon Aiming Concept. I chose the Compact series of ACOGs because I wanted something small and light that would become a part of the rifle rather than something added to it. The 4x scopes were 14 oz vice the 3x model at 3.9 oz. The fine crosshair is advantageous in applications were you want to see fine details and not obscure important sight picture details. I picked amber over red reticle as it is brighter. The reticle has it’s center 20” illuminated which can be used for range finding - the width of the average person is about 18” at 100 yards. The entire fine portion of the crosshair is 40” at 100 yards which will cover the width of a person at 50 yards. And finally I chose the dual illuminated model with its unique BAC to experiment with. I am a bit taken back by the odd appearance of a plastic rod across the top of my scope but if it works who cares what it looks like. When shooting from a dimmly lit area to a brighter one the amber portion of the crosshair washes out but the black outer portion doesn’t so fairly accurate shooting can still be done. Under full sun the amber portion of the crosshair appears as a set of very thin black lines.

 I had one other issue with this model and that was its short eye relief of just 1.4”. I keep my shoulder to the grindstone and my nose to the charging handle so this shouldn’t be an issue. The ACOG sits just less than an inch above and slightly in front of the iron sights. There is a channel cut in the mounting to allow normal use of the iron sights.

The illuminated portion of the reticle covers 20” at 100 yard and can be used for range finding.

The compact ACOG sits just above and forward of the stock A2 rear sight. The short eye relief doesn’t prove to be a problem as the AR series of rifles should be shot with the nose to the charging handle and was designed around this rifle.

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