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Review: Trijicon TA33 – The Most RDS-Like Magnified Optic Available?

This review is going to be a little different than most. I will spend just almost as much time talking about other optics as I will the Trijicon TA33 ACOG which is the subject of the review but please bear with me. I have a point… I think.

The holy grail of carbine optics is an optic that provides red dot sight (RDS) like speed and performance coupled with the ability to ID targets and shoot effectively through most or all of the useful range of the 5.56 cartridge. As with anything we hang on our carbines, the grail optic should also be as compact and lightweight as possible. Most shooters immediately think of low power, variable magnification optics like a 1-4X style scope largely because of the ability to dial the magnification down to 1X which they assume will offer the most RDS-like experience.

I think they may be barking up the wrong tree or at least missing some of what makes an RDS great. The most RDS-like magnified optic is not a variable power optic at all. It is a compact, lightweight, fixed 3X magnification scope called the TA33 ACOG from Trijicon. It might not be the grail optic but it is a real gem.

Trijicon TA33

There is More to an RDS Than Just 1X

I have written before about how the reason the RDS is the default optic for fighting guns is not just that it is 1X. It has just as much to do with the fact that the RDS has long eye relief (basically infinite) and the most forgiving eye box possible. This is what makes it forgiving of the awkward positions and the less than ideal shooting situations that come with defensive shooting. This point is largely missed or ignored by novice shooters.

That is not to say that you can’t be fast with a 1-4X (or 1-6X/1-8X). You certainly can, especially if you choose your 1-4X optic wisely and practice. When you are standing or walking through a course of fire, you likely won’t see much difference at all in your times between a 1-4X and an RDS. However, when you add in some awkward shooting positions, a full on tactical tuxedo (plate carrier, chest rig, etc), and barrier shooting you can start to see the RDS rise to the top. This is due to how forgiving the RDS is of the inconsistent eye placement that comes along with this type of dynamic (forgive me for using that tactical buzzword) shooting.

When you are standing, it is easy to drop your eye into more or less the same position every time behind an optic. Now go to prone. You will likely find that you are now closer to your optic. The same goes for barrier kneeling. Go to some form of roll-over prone or supine position. Your eye is now probably offset to the optic slightly (or at least you are straining to get it centered) and it is probably either closer or further depending on the position. None of this matters with an RDS but with a magnified optic, you have eye box considerations to deal with. It takes time to hunt for that sweet spot to place your eye behind your optic. That is time that would be better spent shooting if you optic allows it.

TA33 on barrier

If your shooting involves awkward positions like this, you will be thankful for the forgiving eye relief and eye box. Photo credit: Eric H

Enter the TA33 ACOG

The TA33 may lack 1X capability but it makes up for it with a variety of eye catching reticles along with the most forgiving eye box and eye relief of any magnified optic I have ever tried. It also happens to be extremely lightweight, compact, and durable like an RDS. It even has a few other little tricks up its sleeve that further cement it as the most RDS-like magnified optic available.

The eye relief on the TA33 is absolutely amazing. It is useable from as close as roughly 1″ to as far as 7”. That sort of eye relief is utterly amazing and while it isn’t the infinite eye relief of an RDS, it is might as well be for the way a carbine is used. If you can get your cheek on the stock, you can probably get a sight picture. This forgiving eye relief means that whether you are nose-to-charging-handle or shooting from your back, you won’t have to spend time hunting for the proper eye relief.

Trijicon TA33GH Reticle

The eye box is equally amazing. There is a massive area behind the TA33 that will still allow a full sight picture through the optic. Even when you are so offset that the view through the optic is partially or even fully blacked out, the eye catching reticle is still visible and will allow you to get a hit at shorter distances. Let that sink in a bit. Even when the view through the TA33 is obscured because your eye placement isn’t perfect, you may still be able to see the reticle and get a hit.

We have established that the TA33 is forgiving in terms of eye relief and eye box but the RDS comparisons don’t stop there. The TA33 weighs around 10 ounces if you replace the heavy TA60 mount that Trijicon includes with the optic. That is about 4 ounces more than a Micro Aimpoint (6 oz) and about 2 ounces less than full size Aimpoints (12 oz). It is typically at least 6 ounces lighter than most 1-4X style optics with their mounts. So, even its weight is very RDS-like.

It also happens to be very compact like an RDS. It is about 6” long and 1.25” wide at its widest point (the objective end). Compare that to the 10+ inch length of a typical 1-4X optic.

FOV: Buzz Kill or Blessing?

Right about now, you are pretty fired up about the TA33. You are probably already cruising the Trijicon website and pulling out your credit card when… your TA33 buzz is killed by the field of view (FOV) numbers that you are seeing listed in the specs (3.7 degrees, 19.3 feet at 100 yards). Step down off the ledge. It isn’t as bad as it looks. It is definitely tight (the tighest of any optic I have owned) but the limited FOV actually works in the TA33’s favor. Let me explain.

A magnified optic with a 1x setting lets you shoot with both eyes open easily because the image through the optic is close enough to what you see with your unaided eye that your brain can stitch the two images together. In that sense, 1-4X optics are very RDS-like. However, the TA33 has a fixed magnification of 3X. The image that you see through it is vastly different than your unaided eye and your brain will not stitch them together but it can rapidly switch between them or even ignore it all together!

The limited field of view coupled with the compact size and generous eye relief of the TA33 are actually what make it so fast up close. The compact size and long eye relief ensure that you can see around and past the optic to allow for a fuller view of what is in front of you beyond the TA33. The limited field of view through the TA33 gives you less visual input when you are up close which makes it easy to ignore the view through the optic and look past it (target focus) with both eyes open, super imposing the bright reticle on your target, like you would with an RDS. It is essentially works like an occluded eye sight that you don’t actually have to occlude.

Trijicon TA33 Top Down

If you do need to take some time to refine your shot, you simple allow the eye behind the TA33 to focus on the image through the optic. It happens in a flash, especially if you practice. This is basically what Trijicon calls the Bindon Aiming Concept (BAC). It can be done with just about any optic made but Trijicon has basically mastered it with their eye catching reticles. I have owned TA31 and TA11 ACOGs which are both great in their own way, but the smaller overall size and tighter FOV really lets the TA33 excel at the BAC over those models. The TA33 is the BAC fully realized.

Other Considerations

The above has really focused in on the RDS-like quality of the TA33 which is really just scratching the surface.  There are a few other things about it that I should note:

  • The available reticles are all very usable. My favorite is the horseshoe since it seems to offer the best compromise between precision and speed.
  • The BDC reticles are more of a guide than a hard and fast rule but I have found them to be accurate enough to get hits on steel at extended distances.
  • The glass in the TA33 is typical Trijicon glass which is to say it is bright and clear from edge to edge. The TA33 is a 3X30 optic so it has a massive 10mm exit pupil which allows it to excel in low light.
  • Some people tend to recoil in disgust at the price of ACOGs. I have never understood that. They are not inexpensive but they are so good optically, that they have always struck me as a solid value compared to other optics with similar quality glass.
  • A number of manufacturers make replacement mounts for the TA33 and I highly recommend that you pick one up. Some of them will bring the total weight under 10 ounces and the pick of the litter is the Bobro high mount that is sold through Trijicon. It preserves the OEM mount height which helps the BDC match up better and helps clear a fixed front sight base.
  • The TA33 is one of the few ACOGs that can accept normal scope caps. That is a huge plus if you want to protect your investment and especially if you want to use it as an occluded eye sight in close quarters or low light situations.
  • One of the best things about ACOGs that no one talks about is their integrated mounts. I like that I don’t have to worry about leveling them.

The TA33 certainly isn’t perfect…

  • Trijicon’s dual illumination system is one of the best things about ACOGs and one of the worst things about ACOGs at the very same time. It is great because it doesn’t need batteries and because it self-adjusts pretty seamlessly… to a point. If you are in a dark area, looking out into a light area, you might find that your reticle washes out. The same is true if you are trying to use in close quarters with a flashlight. I find that the circle dot is eye catching enough when “blacked out” to help but it still takes a moment to find the reticle. This is part of why so many shooters use offset iron sights or an offset red dot sight in conjunction with their ACOGs.
  • I already covered that the tight FOV can be played as a strength of the TA33 but there may be times when you will wish you could see more through the optic.
  • The TA60 mount that the compact ACOGs like the TA33 come with is not a great fit for such compact, lightweight optics. The quality is good and it is bull strong but it is massive and heavy. You can knock almost 2 ounces off the 11.64 ounce total weight by purchasing an after market mount and gain QD capability. That said, even with the TA60, this is far lighter than most magnified optics.

Trijicon TA33GH

Wrap Up

The TA33 may not have a true 1X magnification setting but I think that an argument can be made that it is the most RDS-like magnified optic available based on its compact size, low weight, extremely forgiving eye relief, and massive eye box. It deftly straddles the line between RDS and variable, low magnification optic in way that no other optic can. Its extreme versatility makes it a solid choice for the general purpose carbine. The TA33 is my favorite ACOG made to date.

Eventually, I would like to try one of the TA44S 1.5×16 ACOGs to see where it fits in and how it performs versus an RDS but for now, my long time love affair with the TA33 continues.

Check out the Trijicon TA33 ACOG at Brownells.

Trijicon/Bobro Tall Quick Release Mount for Compact ACOGs

If you happen to like Trijicon’s line of compact ACOGs, you probably know that many of the previously available mounting solutions are less than ideal. The previously available mounting solutions were either bulkier and heavier than necessary or sat low enough that they caused more shadowing from the front sight base than some prefer or threw off the BDC calibration of ACOGs like the TA33. Thankfully, there is now a mount available from Trijicon that gives you the best of all worlds.


The Tall Quick Release Mount for Compact ACOGs (AC12027) is manufactured by Bobro Engineering for Trijicon. It is the same height as the original TA60 mount (1.660″ from top of rail to center of optic) that is provided with many of the compact ACOGs but it is considerably more compact and also offers Bobro’s excellent QD capability. Bobro’s ingenious mounting system is robust, repeats zero, and self-adjusts to most 1913 rails. This mount is exactly what I have been looking for and I have one on the way for my TA33.

Check out the Tall Quick Release Mount for Compact ACOGs from Trijicon.

Trijicon, Please Make This Optic!

Trijicon, you have the technology, ability, and experience to make a great multi-purpose optic for a fighting rifle. All you have to do is combine technology from two of your current offerings.

The ACOG is an amazing optic. It has some of the best designed reticle options on the market today. The way the ranging/BDC (bullet drop compensation) system works is nearly perfect. The biggest thing holding it back is the fixed magnification which slows target acquisition at shorter engagement distances. Yes, even with the BAC (Bindon Aiming Concept), it is still slower than a true 1X or non-magnified optic.

The TR24 Accupoint offers the ability to adjust magnification from true 1X up to 4X. It has glass that is similar in quality and clarity to that of the ACOG which is excellent. It also has the very handy adjustable fiber optic cover to adjust the amount of the light that reaches the reticle on sunny days.

Neither of the optics are reliant on batteries for illumination. This is a strong point on most Trijicon products.

I would be in line for one (or maybe 5) tomorrow if Trijicon were to combine these two optics into an optic that was essentially an 1-4x Accupoint with ACOG like reticle and BDC.

The reticle could be a simple cross hair with a larger circle around the intersection. The circle would serve to draw the eye. If this reticle were to be placed in the first focal plane (FFP), it would appear as a smallish dot when the optic was on 1X which would be advantageous for faster acquisition at shorter distances. The crosshairs would be more usable for precision at longer distances on 4X when the reticle appears larger. Typically, FFP reticles are used to make ranging/BDC systems work at all magnifications. However, I really only suggest the FFP reticle for the reticle scaling reasons listed above. A reticle like the circle-dot, already in use in the ACOG, might also work but it would give up some precision to a reticle with crosshairs.

Add the usual ACOG ranging/BDC hash marks on the bottom stadia line of the reticle and watch this optic fly off the shelves. The simplicity of this ranging/BDC system can not be beat. I would personally like to see it set for a 50/200 yards zero but the standard ACOG 100 yard zero would be fine as well.


  • 1-4X with true 1x on the low end (while you are at it, a 1.5-6x might be nice too)
  • First focal plane crosshair/circle reticle
  • ACOG ranging/BDC
  • TR24 Accupoint form factor (covered finger adjustable knobs, fiber optic cover, etc)

Trijicon, if you are listening, please make this optic!

Tactical Handyman – ACOG Fiber Optic Fix

Trijicon ACOGs are excellent optics for fighting rifles, especially when having to deal with extended distances. The ACOG’s combination of size, durability, and speed make it one of the best choices for an AR-15 optic. The ACOG has been battle tested in Iraq and Afghanistan and has come through with flying colors. It has also become very popular in the competition shooting world – especially 3Gun competition. It is a proven system.

The Problem

One of the ACOG’s best features can also be one of the most annoying. The fiber optic illumination system on the ACOG allows the reticle to glow brightly in full sun and automatically adjust to changing lighting conditions. When there is no ambient light present the reticle is illuminated by the tritium insert. It all sounds great until the task at hand calls for any amount of precision. In full sun, the reticle can be so bright that it begins to flare. This flaring obscures the view of the target and makes it difficult to shoot with any level of precision.

I used to just use electrical tape to mask the fiber optic tube of my ACOGs. However, this is an all or nothing solution. It fixes the flaring problem but it doesn’t allow the fiber optic to gather any light in intermediate and low light situations. This solution was too static. I needed something that was more dynamic – something that would allow me to adjust to different lighting quickly and easily.

I tried making a hook and loop flap that could be stuck to the ACOG and peeled back to varying degrees to expose or cover the fiber optic tube. This worked great in my living room. Once the rifle was actually run through some drills a problem became obvious. The flap would catch readily on my gear, sometimes pulling it almost completely off the ACOG. So this solution was dynamic but it wasn’t durable.

Finally, I took a page out of the 3Gun play book. Shooters in 3Gun have been using bicycle tire inner tubes to cover the fiber optic for years. Typically a piece of inner tube is cut to length and then stretched over the optic. This effectively covers the fiber optic while still allowing for some adjustment by peeling the tube back. Inner tubes are tough and cheap. This idea has a lot going for it. This was my starting point.

The Solution

What I ended up with really works. It is securely mounted on the ACOG and will not snag on gear. It blocks almost all light from entering the fiber optic but also adjusts rapidly and easily to any lighting condition. It costs pennies and is easily replaceable.

Here you can see the cover in place. It is basically one length of tube that has been cut into two loops connected by a strap.

Pull the strap over the elevation knob to allow some light gathering. The short length of electrical tape is there to block the little bit of ambient light that can still to the back of the fiber optic.

Pull the strap over the windage knob to allow even more light. I have found that on the TA11 ACOGs, with their extra long fiber optic tube, this is more than enough exposed fiber optic for just about all lighting conditions.

What you will need:

  1. ACOG equipped rifle
  2. Bicycle tire inner tube – a piece roughly as long as your ACOG
  3. Sharp scissors
  4. Hobby knife (or any knife with a sharp point, I used a Swiss Army Knife)
  5. Electrical tape (optional)


  1. Check that your rifle is unloaded and remove all ammunition from your workspace.
  2. Check it again.
  3. Cut a length of inner tube to roughly the length of your ACOG using your scissors.
  4. Measure the length of the hole you will need to cut to clear the base by laying the tube over the ACOG and marking the locations indicated in the picture.
  5. Cut the hole about two/thirds of the way up the width of the inner tube. The idea is to leave a strap that is just wide enough to cover the fiber optic tube with some overlap.
  6. Trim all of your corners so that they are rounded. Any corners left pointed or square can create stress cracks in the cover as it is stretched.
  7. Cut an angle that matches the leading edge of the ACOG on the leading edge of your inner tube. Shaping the front of the cover like this will help you cover the leading edge of the fiber optic tube.
  8. Stretch the inner tube onto the ACOG and twist it as necessary to cover the fiber optic tube. The fiber optic tube runs at an angle so you will need to the twist the cover so the strap covers the tube. It should be difficult to stretch.
  9. Adjust the fit as necessary by trimming excess material from the inner tube.
  10. Trim around the elevation turret cover with your knife. This will help the cover lay flatter over the fiber optic tube.

Optional Step: You may want to place some tape on the front 1/2 inch and back 1/2″ of the fiber optic tube. This will help cut down on light that may reach the tube from the front of the cover and around the elevation turret.

That Was Easy!

That was simple, cheap, easy, and effective. There aren’t many things in life that you can say that about. Is is easy to make another if this one ever breaks. You could even make a spare and keep it on your gear.

Problem solved.

Let me know if you have any questions!

NOTE: This works best with ACOGs that have long objective ends that project forward of the mount like the TA11 and TA33.

NOTE: Keep your cuts as clean and rounded as possible. Right angles and jagged cuts create stress risers that will cause the cover to rip prematurely.

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