Euro Optic had them on sale for $800 and some change so I decided what the hell. Read mountains of people talking about poor eye relief, not being able to see the reticle very well, etc.

I got it today and this thing is an anomaly. Firstly the actual eye relief is at least double the listed 1.4”. At 1.4” you see more of the inside of the optic than you do the field of view. I know the TA33 is listed bad too, but this one is even more comical.

At optimal field of view exit pupil is right what it should be. At the listed eye relief it’s atrocious. However, if one backs out just a tiny bit and accepts a tiny loss of field of view the exit pupil becomes massive. I’m guessing this realization is why the TA33 exists. Just a hunch, but I’d bet the TA33 uses the exact same prism, and the add on lens is just to align the field of view with the peak exit pupil instead.  

I got the crosshair with amber illumination. The combo I wanted least. I haven’t shot with it yet but my initial impression is the polar opposite of what I expected. Very optimistic and it’s calibrated for M193 which is what I shoot 95% of the time. Glass is typical ACOG awesomeness.

I can’t speak to much beyond my initial impressions, but that alone is enough to label majority of the complaints you’ll see people bring up as complete BS. It’s tragic how overlooked this optic is based on Trijicon’s improper listings and non owners on the internet piggybacking off of it.

Use it the same as a TA33. Distance it to lose a little field of view and the eye box is massive. Yet you can still push forward to get that bigger field of view when you need it.

Attached File

My first ACOG was a 3x24 amber triangle back in 1994.  I mounted it on the fixed A2 handle of a Bushmaster M4A2.  The eye relief was such that I ended up drilling a hole further back in the handle than the factory hole.  The amber wasn't very bright but it was the only option I could find locally.  Remember, 1994 was sort-of pre-internet and 100% pre-internet buying. I used that set up as my "go to" carbine for a number of years.  Back then I had something "cutting edge" and "rare".  I never, once, saw another person at the range or at a gun show with an ACOG during that time period.  I've since owned the newer models:

TA44
TA45
TA47
TA50
TA33
TA01
TA11
TA31

My favorites are:

TA33 3x30 (great eye relief)
TA11 3.5x35 (best overall ACOG but big)
TA31 4x32 (compact but offers 4x)

I only own TA11 and TA31 now.  If I wanted a really compact and light ACOG I'd opt for the TA33 (3x30).

ETA: Amber is my least favorite reticle color.  It has a tendency to "wash out" in bright sunlight.  I owned a number of Trijicon Reflex sights when they came out.  Those were notorious for washing the amber reticle out.  The fiber optic TUBE on the ACOG helps, but not enough for my eyesight. I oscillate between preferring red and green. I'm 50/50 on those two and would be happy with either.

Amber ACOGs are usually the least expensive (in all models). I ASSume that is due to lack of popularity.

That’s the anomaly. The TA50 and TA33 appear to be the same optic and I’d almost bet money they use the exact same prism. People naturally seek the peak field of view, so by adding that secondary lens they can push people to using the best eye box location with a tiny bit more exit pupil.

Point being that if you allow shadowing to slightly reduce the field of view on the TA50 to match the TA33, the eye boxes are nearly equal. If you use the TA50 at peak field of view and listed eye relief, it’s dog shit. Likely a fault of the prism geometry design and exasperated by Trijicon listing the eye relief wrong.

And amber isn’t my first choice nor would I recommend it but it gets plenty bright with the crosshair reticle. Looking from shade to a white background on a sunny day it’s still incredibly bright. I’ve never used one with the triangle reticle. For almost $300 cheaper I sure won’t complain.

I always wondered if the useable eye reilef is listed lower like the TA33 and TA47. Although my TA33 manual says 3.6" IIRC, definitely the 1.9" listed on Trijicons website. Thanks for confirming.

I think that the TA50 is the most underappreciated ACOG. To me, it feels like a miniature TA31, with fairly short high relief, but a generous field of view. It's also very lightweight, and has pretty good reticle choices. I currently have one mounted on one of my primary go-to rifles, and it replaced a TA33. I found a TA50 to have a more useful field of view, and a less cluttered reticle even though they are both horseshoes.

TL;DR: The prism geometry doesn’t match the objective lens size.

The prism in this has more horsepower than the body can handle. I genuinely think they had two design teams on this that clashed. At peak field of view you see a ton of the inside of the optic and are subject to sensitive exit pupil error. If you move back away the eye box becomes immensely larger but you lose field of view. This means the peak field of view and the peak exit pupil are misaligned due to improper objective lens sizing.

The only time the prism shadows is at the peak field of view. Yet the objective shadows at the peak eye box. It’s like having 500 horsepower in a go kart. There’s just no way to put the power down.

The TA33 is an attempt to fix that, but instead of spending insane money on modifying the forging to fit that bigger lens, they chose to half ass it with the extension. In doing so they pushed the lens forward which reduced field of view but did align the objective with the prism in a backwards approach of reduction.

If this optic had been made a 3x30 without moving the objective lens, it would have been the ACOG everyone wanted. No ifs, ands, or buts, it would be insanely good. Think 3.5” of eye relief with a 30 something foot field of view in a bomb proof package under 10 ounces. Easier said than done after you dumped millions of dollars though.

It’s still not bad though. I set mine up for peak eye box (about 3”) instead of peak field of view like most. This means I get a little objective shadowing but I can still crunch forward and access the max field of view when needed. I would honestly recommend the TA33 as most people either won’t recognize this, or they’ll just be understandably bothered by it. If you’re mounting it at peak field of view, it’s not going to be a very good time. If you mount it at peak eye box it’s still a very decent little optic, if you can compromise on your edge clarity.

I’ll be keeping it but with the head shaking understanding of what could have been.

Had one, did not like it, sold it.

For a soldier in a combat zone, great optic.

For a guy at the range, many better options.

That is a great set up.

I got one for my son's rifle. He likes it a lot and I do too. I have a 33 on my primary

Heard back from Trijicon. They claim the horizontal stadia marks serve no purpose. I think they just couldn’t find out what they’re measuring. The BDC stadia matches a human torso for ranging but stops at 300 yards.

I suspect the wind holds match up with my ACSS stuff but can’t confirm until I get my TA50 back from Cerakoting.

By their illustration, it looks like 10, 15, and 30 mils.

I’ll try to find out. I also suspect the height of the stadia in the wind holds is for ranging too. What, I don’t know.

Attached File


I also realized why I like this better than the other ACOG crosshairs I’ve tried. It has an extra stadia line of illumination. May not seem like much but it is for me. Much easier to pick up.

Some closing thoughts.

I like this thing. A lot. As in it might be my favorite optic ever. Yes, with amber illumination. Yes, with a crosshair. The precision on it is great but with the extra BDC stadia illumination versus the other crosshair models it’s super easy to pick up.

It’s super light. Even with a piggy back RMR you’re looking at right about 10 ounces. Some LPVO mounts weigh that.
Attached File


ETA: Weight with ADM mount, RMR mount, and Type 2 RMR.
Attached File


I measured and I’m running it at 3.75” of eye relief. I don’t shoot NTCH. I do see light shadowing which reduces the FOV by about 15%, but this is where the eye box peaks. If my cheek is touching the stock at all, I can make hits. I just arch my head forward a little bit if I do happen to want that full FOV.

Attached File

Attached File


The TA50 is not the black sheep, it’s the optic no one knows what to do with it.

I think I figured it all out. The BDC stadia is known to match the width of a torso at the given meter markings.

Attached File


The distance between the horizontal stadia (figure A) is about the exact same as the ACSS Raptor horseshoe width, which is based on military data of the average movement speed of a military aged male with a load out at 100 meters. The PA is very slightly smaller, likely due to using yards instead.

The horizontal stadia height (figure B) appears to match a human torso’s height at 100 meters as well.

Figure C looks to be the same applied at 200 meters. I would imagine the last stadia line is 300 meters as well, but we’re getting dicey here as I lost my range finder and only ever checked yards on my street.

Very unscientific and could be off, but based on sending the boy for a run and areas I know from yardage, if this isn’t exact it’s damn close on the measurement side. The 200 meter run speed seems a little sketchy but not sure what else it could be.

I've been trying to tell people this about the 4x acogs.

Yes, the eye relief is short... IF YOU WANT MAXIMUM FOV. But you can back off the scope another couple inches and still use it just fine, except the further back you get, the more it feels like you're looking through a straw.

Wait, what other acog is described as looking through a straw? The ta33!

I never understood the mechanics as you've explained here with the prism but i think the same applies to the ta31.

I'm practice, i can scoot forward if i really want max fov, which is huge. But I don't need to be right there to use the scope effectively.

I put a ta01 on a 308 scar for a while and shot it based on this principle... Not shooting with max fov, but rather where I'm comfortable in the eye box.

Attached File

Yep, and I’ve come to a realization that they probably did this all on purpose. Over sizing the prism gives you two different use options based on eye placement. Fast and forgiving, or wide and dialed in. I really do think majority of people are using ACOG’s wrong, and even if you consider how BAC works, it makes sense that you’re not going to want peak FOV for it to work better when you need that fast forgiving eye box.

I threw my TA50 on my 308 carbine to try out and I’m definitely getting another one instead of a TA11 as planned. Just have to figure out drops.

Off topic, but what the heck is that rifle on the left?

It's a mag-fed, single shot, manual feed Solo 300 upper on a lower with a kns pic rail adapter and sig stock.

It has a 6" barrel 300blk with no gas port and a left side straight pull bcg.

Also a dedicated sig srd ti can that is really effective for 300blk.

With subs it sounds like a suppressed subsonic 22lr, but with a lot more ass on the other end.

Click.......... *Steel clangs* ...or *thwack on the animal*

I put it together when my dad had a racoon or something eating the feed problem on the ranch but on a side close to neighbors and i didn't want them to hear us shooting them at night with nods.

It's much quieter than a subsonic semiauto 300blk, and even a normal 300blk with the gas turned "off" or something.

But it's smaller and more compact than most bolt action rifles, and if you do go the bolt action route  it would be a lot more expensive. Plus this maintains the familiar AR manual of arms and compatibility with accessories, like IR lasers and nv clipons, etc
Attached File


Eta: also you can use the lower with a dedicated 22lr upper when you're not using the 300blk.

Attached File

So I think I’ve reached my final iteration in this thing. Got the RM54 painted but my two year old can of Alumahyde shamed me. Good enough though.

Got the killflash in for it. Unlike the TA31 there are no provisions for attachment so it’s a bikini strap thing. I thought it was going to break and I’ll be honest, it’s a pretty shit quality unit. Unlike the other ARD’s I’ve used this one definitely darkens to the image significantly.

I decided to use it to my benefit though. The amber crosshair is stars in your eyes bright in the sun and I wasn’t happy with using tape. I bought some adhesive Velcro and went to work on a more permanent solution. This is a prototype and I’m even debating having a more refined and professional version made for all of the major ACOG models. No over lap, no adhesive required, stretch form fit, sewn, laser cut, etc.

Illumination moderated to being what I call perfect brightness on a sunny day.

Attached File

Attached File


Here it is set for a wide open position if needed
Attached File

It sounds like you are trying to invent a condom for the fibre tube. LOL

Basically.

For $4 and 10 minutes of time I have a long term solution to avoid burning my retinas. No tape to come loose, and no inner tube wrap that’s hard to adjust.

Just got done reading the whole thread, and it seems to me like this should work just the same with the TA31. Mine is currently mounted like this:



What I’m thinking is this: instead of having it mounted that far back, for ‘proper eye relief’, and then extending the stock a couple notches when shooting prone to maintain that eye relief, I could just mount it a couple slots farther forward to get maximum eyebox when shooting standing, and my eye position would naturally move forward to get maximum field of view when shooting prone.

Am I following this right? Does that make any sense?

Correct, kinda. I don’t shoot NTCH so mine is set to give me the most forgiveness offhand/standing.

I haven’t tried it with a TA31 but I’d imagine it’s the same. You don’t even have to unmount it to try it out. Just move your head back and test the off axis forgiveness to see where the peak eye box is.

The TA11 it doesn’t work as well since the FOV and eye box are aligned. Hence the TA11 being a boat anchor to achieve that.

How is the TA50 eye relief compared to the TA31? Better, about the same, somewhere in between?

Better. Here’s a picture a guy posted on YouTube. Not sure why he set them at the end of the table instead of actual eye relief but it shows the difference.



I still think it’s best run at peak eye box instead.