The Trijicon ACOG (Advanced Combat Optical Gunsight) line of scopes is a battery-free, combat-proven optic built to the highest of standards.

But there are many types of ACOG scopes, so we developed this guide to help you find the right scope to suit your needs. First we will will discuss the different features and specs of the scopes, and then we included handy comparison charts that show a side-by-side comparison of the different models.

Magnification, objective lens size, and eye relief

This is where the scopes differ the most. The best sizes for the AR-15 are the 4×32, 3.5×35, and the 3×30. These 3 sizes are by far the most popular types of ACOG’s.

4×32 ACOG’s (TA31, TA01, and TA02 series)

These are the most popular ACOG’s (the US Military favors the 4×32). They feature 4X magnification and a 32mm objective lens.

The scope has the shortest eye relief of the bunch at about 1.5″ – this means you need to shoot with your nose to the charging handle (some people don’t like this, but that’s how you’re supposed to shoot anyway!).

But the larger objective lens and shorter eye relief means it has the largest field of view of the bunch. At 100 yards, you can see almost twice as much area through this scope vs a 3×30 ACOG. The scope is fairly light at 14 oz including the mount.

If you’re willing to give up some eye relief for an incredible field of view and higher magnification – the 4×32 is the ACOG for you.

Check out the comparison chart of the 4×32 ACOG scopes >

3.5×35 (TA11 series)

This scope features 3.5X magnification, and a large 35mm objective lens.

The 3.5×35 ACOG has good eye relief at 2.4″, and a fairly generous field of view – 29 feet at 100 yards. This is a great all-around scope because it really balances field of view, magnification, and eye relief. The only problem is the weight – at 18 oz (including the mount) it’s about 4 oz heavier than the other scopes.

If you want a great all-around performer, and you don’t mind the extra weight, this may be the right scope for you.

Compare current ACOG models at AT3 >

3×30 (TA33 series)

The 3×30 his a lesser 3x magnification, and a smaller 30mm objective lens.

Where the 3×30 excels is eye relief. Trijicon claims this scope has a 1.9″ eye relief but this is wrong – it’s more like 4 inches! However the field of view on this scope is only 20 feet at 100 yards – almost half of the 4×32 scope. The smaller objective lens means this scope is light – only about 13 oz including the mount.

If you want a small, light scope with incredible eye relief, check out the 3×30 – just be aware the field of view is smaller than the other types!

Caliber

AT3 Tactical carries ACOG’s for .223/5.56, .308, or 6.8 SPC calibers – simply choose the one that matches your rifle. The reason this matters – the reticle has “bullet drop compensating” functionality. You’ll see little numbers on the reticle – when shooting at further distances, you can use these numbers to adjust your aim and compensate for the drop of your bullet.

Compare current ACOG models at AT3 >

Reticle style

For the style and color of the reticle – it really comes down to personal preference.

There are basically 5 types of reticles:

• Chevron – this is what the military uses – it looks like an upside-down V. Tricjicon calls the military version the “RCO” but it’s really just the same as the regular chevron.

 

 

• Triangle – almost the same as the chevron, except it’s a little pyramid instead of the “V” shape.

 

 

• Donut – it’s a circle shape. Some people find this shape a little less precise but your mileage may vary.

 

 

• Horseshoe/dot – has a large “horseshoe” that surrounds a small dot.

 

 

• Crosshair – the classic crosshair we all know and love.

Reticle Color

Again, this one is mostly preferece. Trijicon offers the classic red color, as well as green and amber. The green and amber tend to appear as “brighter” than the red, but they can sometimes blend in with backgrounds.

For example green may be difficult to see when there is foliage in the background, and amber can blend in with dead grass or sand. When in doubt – we recommend red (there aren’t too many things in nature that are red, so chances are the color will always stand out).

Illumination type

One of the greatest things about the ACOG is that it doesn’t require batteries for illumination (with the exception of the TA02). Most of the ACOG’s use a combination of fiber optic (for daytime) and tritium (a substance that illuminates at night).

The TA01 series ditches the fiber optics, so this sight only lights up at night (during the day, you just see the black crosshairs). And as mentioned, the TA02 series uses batteries to provide LED illumination.

Included accessories

By far the best add-on for the ACOG is the RMR (Rugged Miniaturized Reflex) sight. This is a tiny red-dot reflex sight that sits on top of your ACOG, and it works perfectly for transitioning to close quarters situations where magnification is not needed.

Another important thing to look at is the type of mount included with your ACOG. All of the scopes can be mounted on the AR carry handle, but many of the scopes also include a picatinny rail mount for use on a flattop upper.

Trijicon ACOG Comparison Chart

4×32 ACOG Models at AT3 Tactical

Eye relief: 1.5 in.   Field of view: 37 ft. at 100 yards.

Compare current AT3-listed models below. Click a model or reticle image to view the matching configuration and current availability. Models without a current AT3 product listing are omitted.