Hello. I am in the process of building a CAR for personal and home-defensive use, and would appreciate some guidance concerning my choice of optical device. I have pretty much settled on the ACOG TA11, but I still need a bit more information on use of the offered reticles.

First, with regard to the TA11 red donut reticle, which is shown on the following web page …

http://www.trijicon.com/user/parts/....cfm?PartID=146

… I understand that the donut should be sighted dead on at 100. It looks to me like the first line below the donut is 300. Is that correct? If so, what is the aiming point for 200?

Second, I notice that the TA11F, which is shown on the following web page …

http://www.trijicon.com/user/parts/....cfm?PartID=151

… is calibrated for use on a flat top, while the TA11 is not, and I do not see a red-donut TA11 calibrated for a flat top listed. It would seem to me that mounting the TA11 on a flat top wouldn’t throw the aiming point enough at 300 yards to make any substantive difference. Correct?

Third, has anyone ever tried to use the red-donut TA11 as a CQB sight? How'd it do?

Thanks for the assistance.

Regards,
Jon

Man, we should really make a ACOG FAQ!

You're correct on about everything you said. The donut reticle is callibrated to be on a carry handle. The Chevron is callibrated on a flat top. The difference will be quite minor until you get out there to say 400 yards and beyond.

With the donut, you can zero the top oftghe reticle for 100, the center of the donut will be a 200 yard zero, bottom of the donut is 300, then the first line on the BDC reticle will be 400, and go on down to 800.

TA11 has the Bindon Aiming Concept (BAC), and with practice will be able to be very quick as a CQB sight. Are you familiar with the BAC?

Take a look at the EoTECH Holosight for CQB/Home Defense it's faster, intuitive and 1/2 the price.

Roger that.  My Eotech 552 rocks.  Cool gear and budda bing, up pops my ARMS40 rear sight if I need it.  Can use one, the other, or both.  Takes the same batteries as my TV remote and dictation recorder.  Wahoo.
C

Whats the URL for this EoTECH sight you speak of???

Granted, the Eotech is a fine sight. But it is NOT an ACOG. It is half the price but it also about half as useful. I admit, the half it is useful at (CQB to moderate ranges) will likely be the half you spend most your time shooting. But the EoTech is not going to be much help at getting precision on those targets out past those moderate ranges (say 200 yards?).

The Eotech is also very battery dependant. It has among the shortest battery life of all the quality unmagnified dot optics, and once the battery is dead, the optic is useless. ACOGs are not battery dependant at all, and even if the reticle werent lit, the reticle will be black and still every bit as usefull as a standard scope.

Please dont get me wrong, I'm not here to bash EoTechs, I think they are fine optics and fill a very good role. But the ACOGs we're speaking also fill that role, and whats more, exceed the usefullness of EoTechs. It's plain and simple.

I've looked at the TA11, TA31, Aimpoint, EoTech 552, and Leupold CQT. Of the different sights, the TA11 was my favorite general purpose sight. It is a great day/evening sight that can still be used as an effective CQB sight.

However, there were a few things to keep in mind about the sight. First, it is well-designed but still a rifle scope. Even with the generous eye relief, the ACOG doesn't offer the flexibility of firing positions that the Aimpoint or Eotech do.

It isn't parallax-free like the Aimpoint and Eotech and doing weak side transitions (for firing around cover) or firing from less than optimum eye relief will result in minor variations in the point of impact.

Also, the TA11 relies on tritium and fiber optic to self-adjust the brightness. Under some lighting conditions, the donut can be too bright and will blur into a 4 MOA dot.

The range hashmarks on the reticle are also tiny and difficult to see. For moving targets or fast acquisition, they are useless (then again, how many people are going to try a 400yd shot on a moving target?).

The TA11 is also big when compared to the almost identical (performance-wise) TA31. All that extra size buys you is a better exit pupil (although the TA31 is already at the maximum limit the human eye can use) and another inch of eye relief. For less cost and less weight, the TA31 offers a little more magnification, a more compact package and a better field of view at the expense of some eye relief.

Having said that, I'm interested in buying the same TA11 that was mentioned to you in the TF thread, so I had to dig hard to think up every negative aspect I could about them.

Under 200, I think the Aimpoint and Eotech are faster and quite tough. They are also better suited to most competitive and defensive/CQB shooting.

However, if I could only have one scope to serve every purpose, I'd go with the TA11 or TA31 (depending on how much issues such as size and eye relief are important to you) because if you can't acquire the target, your chances of hitting it drop significantly.

Hi, guys. Thanks for the replies.  I did a good bit of research on optics before deciding on going ACOG.  I have not shot with a TA11 yet, but I have had the pleasure of using a 4X ACOG, specifically the TA01, and it was a great fit for me.  No flies on the EoTech or Aimpoint, but the ACOG is what I decided to go with based on my very subjective needs.  

new-arguy:  Yes, I am familiar with the BAC concept, but only in a rudamentary way.  It was one of the reasons I liked the TA11 so much.  

So, from what I'm getting here and elsewhere, it would be correct to say that if one sighted the donut dead on at 100, then the first meridian line would be the aiming point for 200, and on down as distances increased?  Or would the first meridian line be for 300 with the donut dead on at 100?

Thanks again for the responses, folks.  
Best regards,
Jon

Bartholomew_Roberts:  Just saw your post; must've missed it while I was writing my last.  One of the most informative posts I've read - chock full of relevant info, and I do thank you, sir.

I was not even aware of the TA31.  Looked it up, and you're right - it IS most interesting.  The Trijicon pages indicate that it's over two whole inches shorter and four ounces lighter than the TA11.  Since this is to be a personal defensive rifle, one of my primary goals is to keep it unobtrusive as possible, and that means keeping its dimensions to a minimum, and two inches shorter is a LOT.  Not sure yet what all the trade-offs are, but they don't seem too dramatic - slightly more course adjustments (1/3 vs. 1/4 minute clicks) and .5 more magnification. Looks like I have another option to consider, but don't you go and snake me on that TF scope yet!  ;-)

Looks like you went through 'bout the same analysis as I and reached the same conclusion - that if one were looking for a do-it-all optic, the TA11 will be hard to beat, as long as one remembers that while it will do the job at both close quarters and normal rifle ranges, it will not do so as well as a separate, specialized unit for each application.

Oh, and I did not mention the Leupold due to high number of unsatisfactory reports I read concerning them.  (As a long-time bolt gunner and fan of Leupold scopes, I find that very difficult to say!)  

Regards,
Jon

Also remember that a longer eye relief gives more leeway to where you can place your head in relation to the scope.  Same thing for greater exit pupil... you can have your eye further right or left and still have the full sight picture.  I find the TA11 easier for me to look through if it is brought up quickly in a snap shooting scenario or if shooting from an akward angle.  The narrower field of view and longer eye relief also yeilds a better field of unmagnified view.  The TA11 is a better CQB optic and the TA31 a better precision optic in almost every way.  The only part of this that does not hold true is the finer adjustments on the TA11.

Optics are always a comprimise.  The eye relief, exit pupil, magnification and field of view will determine the size and placements of the lenses.  It is an exact science.  The features of the TA11 fit me perfectly.  Perhaps they do not for you.  The TA11 is the size it is because of those features and it cannot be had in a smaller package.  

Quoted: The Eotech is also very battery dependant. It has among the shortest battery life of all the quality unmagnified dot optics, and once the battery is dead, the optic is useless. ACOGs are not battery dependant at all, and even if the reticle werent lit, the reticle will be black and still every bit as usefull as a standard scope.

I read that using AA batteries in the Eotech the life expectancy is ~350 hours plus it has a programable auto-shut off. By contrast the tritium in the ACOG is good for 10 years, but gets dimmer year after year. My question is - what happens when the lights go out? Is it possible to have the tritium component replaced? On the other hand I can go to 7-11 and get some extra "AA"'s... Just food for thought. Any comments?

I have a TA11 and really like it.  While it is true that between the fiber optic and the tritium that the donut reticle can get really bright in direct sun, I have not seen it glow into a single solid circle.  That being said, if that is a problem, you can cover the fiber optic.  I find that the tritium is still readily visible in full sunlight with the fiber covered.

As far as the drop scale, keep in mind that it is calibrated for specific ammo from a specific barrel length and mounting position and firing the gun that is level.  Change any of these and the scale is going to not be as accurate as it can be.  However, the differences are miniscule.

Also note that in the TA11 manual, Trijicon notes that the TA11 adjusts at 1/4 inch at 100 yards.  If you need to move the point of aim by one inch, then you make 4 clicks.

HOWEVER, the manual also notes that the scope is to be zeroed at 100 meters, not yards and that the drop scale is in meters, not yards.  I don't know if they meant yards or meters, but whichever it is, they should not have mixed scale categories as there is about a 10% differnce between yards and meters.  

I bought a ta01 nsn without the BAC and was disappointed with the scope inside of 50 yards.  So I ended up mounting a Docter Optics red dot above it.  I love this combo.

The red dot has infinite eye relief and is parallax  free.  It allows for all kinds of awkward shooting positions.  Its high placement above the acog ocular lens allows an unobstructed field of view so you can use all of your peripheral vision.

The battery life is said to be 3 to 5 years (mine has been on for 10 months and is still strong).  Four $2 batteries should last longer than a tritium lamp.  

I hope to be able to use it as an occluded eye sight in conjunction with a night vision monocular worn over my left eye (still saving for the N.V.).

All in all I think this combo is great from 0 to 600 meters.  

I have never used an acog w/BAC, but it seems the eye relief might be an issue when using the BAC in close and quick. Am I wrong? Also, what happens when the tritium lamp dies and its illegal to have radioactive material or guns are outlawed altogether?

I too bought a TA-31F because I think it is about the best all around scope out there.  Great for the distance shots, and the BAC is good for the closer in stuff, but I still had concerns about the 0-50 yard scenario, so I mounted a Surefire L72 laser on mine.  If I need to switch hands for a right hand corner or just about any other CQB application, illumination is just a push of the button away, and I don’t sacrifice anything at 200 yards +.  

M4_A3 That sounds like a good solution. What do you have to give for a Surefire L72?

Quoted: I read that using AA batteries in the Eotech the life expectancy is ~350 hours plus it has a programable auto-shut off. By contrast the tritium in the ACOG is good for 10 years, but gets dimmer year after year. My question is - what happens when the lights go out? Is it possible to have the tritium component replaced? On the other hand I can go to 7-11 and get some extra "AA"'s... Just food for thought. Any comments?

Tritium does not get weaker year after year. It has something called a half life. Which means, unless mistaken, after a certian time it will be half as bright. Even so, the mannual states the tritium has a useful life of 20 years, and is guaranteed to glow for 15. 15 years = approximately 120,960 hours vs. MAX life of 350 hours for the EoTech. I'll take 120,960! I didn't even count leap year And if the "lights go out" the fiber optic will STILL light the reticle in lit conditions, and the reticle will appear black like any other rifle scope when there is not enough light to allow the fiber optic to power the reticle. On top of this Trijicon will replace your tritium for about $35 if need be.

In addition, the 350 hour life on the Eotech is only in one model, which happens to be the biggest, bulkiest, heaviest and most expensive of all the models (granted, still not as much as an ACOG). And it only gets that long a battery life with LITHIUM AA batteries, not standard AA batteries. Last time I checked, lithium AA batteries were not available at 7-11.

To those of you who have used the TA11 or TA31 at night, have you noticed whether or not the light from the tritium reticle in the scope ...

1.  ... interferes with the shooter's night vision?

2. ... lights up the shooters face enough to turn it into a target?

3. ... blocks the shooter's ability to see the target?

Thanks again.

Regards,
Jon

Quoted: 1.  ... interferes with the shooter's night vision? 2. ... lights up the shooters face enough to turn it into a target? 3. ... blocks the shooter's ability to see the target?

1. No
2. Hell no
3. No... but(!) that can be dependant on the size and distance to the target. These are not fine cross hair reticles. They are somewhat larger and if the target is very small, or, very far, then yes, the reiticle and cover your target. Just to clarify, this has nothing to do with the glowing reticle, merely the size of the reticle.

10-4, new-arguy.  Your assumption as to my meaning re: number 3 is correct; was refering to light wash from, not size of, the reticle in relation to the target.

Thanks for your usual on-point response.

Regards,
Jon

For "personal and home-defensive use" you would be better off with the Eotech or Aimpoint.  Magnified optics are less than ideal at very short ranges, even with the BAC.

With BAC magnified optics, I tend to disagree. You give up very little to nothing in speed with a BAC optic, and you get a lot in return.

imposter - My apologies for not making clear in my initial post that I want my rifle capable of use at ranges farther than CQB.  With this being the case, I am going to go with the TA11 for the reason new-arguy mentioned.

Regards,
Jon

I have the following optics on my ARs: Elcan, Aimpoint and a mini ACOG 2x20 with BAC triangle. I must say that the mini ACOG is my favorite of the bunch. The huge 10mm exit pupil makes low light ability great, enlarges eye relief zone and lessens eye fatigue.