View Full Version : Rangefinding in the dark with only center-illuminated ACOGs
Hi all,
To anyone who may be able to help with the following questions:
1) As far as I'm aware, the only ACOG scope which has the entire reticle illuminated is the TA01. Does anyone have know if the the non-illuminated parts of the crosshairs/rangefinders/reticle on the other scopes are visible enough at nighttime in order to estimate range with them? Or is really only the center visible.
2)The TA01 I had been issued in the past also had the reticle on the right-hand side of the picture I attached, which allowed rangefinding according to head width, shoulder width and torso profile (same with the red-circle I later used) - however none of the ACOGs that I can find for sale online have these side marks - only the horizontal lines below the crosshairs and the hash marks on the chevron models. Anyone know why this can't be found? Also does anyone know the reason why the only model which had full-line illumination was the ta01, and all subsequent Trij models had only center-illumination?
3) Which of the ACOGs, if any, allow for mil-dot range estimation?
Thanks in advance, great forum you have going here.
Just wanted to know as well if anyone has an opinion or experience with the iron sights on the ta01NSN, and whether they're in any way useful (just for center of mass, quick acquisition, at ranges only up to from right near to 15m or so)..
LettersFromEarth
10-26-08, 21:54
Just wanted to know as well if anyone has an opinion or experience with the iron sights on the ta01NSN, and whether they're in any way useful (just for center of mass, quick acquisition, at ranges only up to from right near to 15m or so)..
The Irons are pretty useless IMO. When the TA01 NSN came on line in 1995 or so there might have been a real need for same given that such things as MRD's and/or Mirco Aimpoints were not far along in their development or were not even thought of then.
BTW--Interesting reticle pics. These were Trijicon reticles?
Have never seen that reticle from an ACOG.
Yes they are... i was taught rangefinding only on these. If a man's head width fits between the first two side marks = 200 meters, btw inner two, 300 meters, if shoulder width between first two, 400, second two 500. The lower marks on the vertical are for measuring a figure in profile - the first one (marked 4) if it fills the width of a figure in profile - 400 meters, the lower mark -500. (on the redpoint, on the crosshairs it's the 3rd and 4th). In any case - I don't know why none of these are shown on even the trijicon website, much less not for sale.. if anyone knows, I'd appreciate the info.. I've never seen the reticles that are shown on their site, where at the bottom edge of the reticle on the ta01 there are two small circles - - are those supposed to be for mil-dot?
Bout that the irons are useless... i mean just for cqb point shooting at no more than a to 20 yards or so - - ranges at which even just point-shooting would get you a center-mass hit for the most part - it's just that having the trij on obstructs the view of the front sight post, and so thought to use the ghost ring for pointing - unless there's something inherently wrong with them. I was more looking for something inherently wrong with them as such, more than the merits of iron/reflex-redpoint at close-range.
Lettersfromearth - why didn't you like the TA01NSN? (you had written on another thread that -) If you have experience with it you could answer my other question - seeing as only the center of the crosshairs is illuminated at night - is the rest of the crosshair still visible enough to see them? Also what's your opinion of the amber vs. red? Thinking of getting the chevron instead of another ta01, but it just doesn't seem to me accurate enough for longer ranges vs. a crosshair.
Have never seen that reticle from an ACOG.
I was in the Israeli army (I'm now living in the US) - these two reticles were the only two trijicons I'd ever seen and were what was issued to designated marksmen. Perhaps they were somehow modified to IDF specifications, or .. dunno. For snipers we used the leupold m4. This year they also started issuing new ACOGs with the red chevron and side hash marks, I understand.
I'd actually be very interested to find out why these reticles are apparently not found (or even used) in the US - if anyone knows - I'd be interested to know. The range estimation method I get from the reticles I see here (torso width on line # x= x hundreds range) seeems pretty meager to me, having no way to measure in profile or in situations where the head is visible.
LettersFromEarth
10-28-08, 12:05
...Lettersfromearth - why didn't you like the TA01NSN? (you had written on another thread that -) If you have experience with it you could answer my other question - seeing as only the center of the crosshairs is illuminated at night - is the rest of the crosshair still visible enough to see them? Also what's your opinion of the amber vs. red? Thinking of getting the chevron instead of another ta01, but it just doesn't seem to me accurate enough for longer ranges vs. a crosshair.[/QUOTE]
Thanks for posting here, sir. I'm a fan of the IDF and enjoy reading/hearing about training, tactics, and equipment in use by you and yours. Please keep the posts coming and welcome to our forum.
Now, the TA01NSN is a good optic and many folks hold the opinion that it (NSN) is the best optic for their needs...Im just not one of 'em. My reasons are as follows:
1) Too fine of a reticle. For me its harder to see. Some folks like it stating it allows them to make a better shot or produce smaller groups over other ACOG choices (such as the TA31F) but I find that shots 100m and under can be made faster and be just as well placed using a later generation ACOG with the Fiber Optic illumination (TA11, TA31, TA33, ect). ETA--Yes, only the center of the NSN is lit. Sometimes, under the right conditions, you can see the rest of the reticle but it doesnt make a difference really.
2) Illumination. Not all daytime enviorments will allow you see the fine reticle of the TA01. Later generation ACOGs, having the ability to illuminate its reticle through its FO tube, have an advantage IMO in all lighting cond. Some have claimed that later generation ACOGs can be too bright in certain lighting situations (outside at night or an average sunny as all hell day in Iraq) but given that later gen ACOGs can be made "less bright" (using speed tape over the light tube) the reverse can not be applied to the TA01; or making it "more bright".
3) Short ER. I could never warm up to the fact that I had to wear the NSN like a Borg implant (inner NERD now showing:)) Factor in wearing a pair of Wily-Xs (goggles) and a Kevlar bucket on my head and that about done then deed for me regarding 4x ACOGs.
Some users of the optic had no problem driving their gun just fine with it. I had the combo for two years or so and I just didnt like it. I could get the job done with it and I did but...
As for the Irons on top--They will work as you say from 15 to 25meters or so. But I found that I could hit at that distance faster by just looking over the ACOG, indexing the target with the M4s front sight and shooting. That worked for me. You might find something else works for you. Take care and again Welcome To Our Forum.
BTW--Red or Amber is up to you. Some cant use one/some cant use the other. Try out both and make the choice.
Thanks for the kind words.
You're right that at room-clearing distance it's point-shooting from the shoulder anyway. I also understand that the tritium in the irons is an exposure factor in the nighttime or in terms of being detected in NV.
We always had put electrical tape over the fiber-optic band for zeroing and for long-distance encounters or when precise accuracy was needed. I guess I just have an emotional attachement to crosshairs, (I found the Leupold 4 to be a wonderful scope, although the nightvision scope we used, the Aquilax6 is terrible, would be interested to know which nv scope is used with the m-24 or the SR25 in the US) and to the accuracy it provides and the groups I can get with it on the range... but in terms of a combat scope I'm aware that the difference in target-acquisition time between the black crosshairs and the chevron is enough to override that, although maybe the T31 crosshair models that have only the center illuminated change that.. Guess I'm really trying to make more of a designated sniper thing out of an assault rifle and a platform that's really not built for it. For various reasons, I don't want to put on a Docter back up scope on trop of the trij, although really in terms of what I'm looking for, the MRD on top of a ta01 would be great, I guess.
Terms of the eye relief - I hadn't had a problem with it - we only use the M4 with the adjustable stock anyway - we hadn't got any M16a4 and the older ones with the fixed stock are no longer in use except for some basic training. The short eye relief I feel helps seeing as many times when I'd be using the scope, I'm wearing ceramic armor +combat vest which forces me to use a fully closed stock (guess it depends on your arm length :))
Does anyone know where I can find or download a manual for any of the chevron t31 ACOG scopes which explains how range estimation works in that reticle? (and the placing of the chevron at different ranges), or explain it themselves?
It is my understanding that the base of the chevron is supposed to be shoulder width (18") at 300m, and the lower hash marks do the same for their respective ranges. I can probably dig up a manual though.
Edited - can't seem to find my manual.
It is my understanding that the base of the chevron is supposed to be shoulder width (18") at 300m, and the lower hash marks do the same for their respective ranges. I can probably dig up a manual though.
Edited - can't seem to find my manual.
OK, well if you do, it'd be nice, I'm trying to figure out how the reticle works for measuring range of a figure in profile, and of head width.
lettersfromearth - the other thing that's good about the ta01 with the full-line illuminated reticle as opposed to the center-illuminated ones is that it allows for range estimation at nighttime - whereas those where only the center of the crosshairs is illuminated do not.
LettersFromEarth
10-28-08, 18:33
Yes, for some, that can be good. BTW--I saw a photo of an IDF troop using an ACOG mounted on his Tavor. What, if any, is your opinion of this new bullpup rifle?
I'm still at a loss at to why the reticles that appear below, I can't seem to find those models anywhere for sale and nobody knows them. I can only think that they were either a military model not sold (not logical, because enough military and ex-military people read my questions) or some modifications were made? Wrote to Trijicon to try and figure it out.
http://photos-b.ak.facebook.com/photos-ak-snc1/v341/175/26/544066116/n544066116_1966689_8081.jpg
This below is the rangefinding we used in these reticles. It seems that only in the ta31rco models is there something similar. (edit: i see the picture comes out a little small - the head is head length 200 outer 300 inner, shoulder 400, 500)
http://photos-a.ak.facebook.com/photos-ak-snc1/v341/175/26/544066116/n544066116_1966776_5596.jpg
Would be intersted to know if it's completely different from the way they used in the us military..
LettersFromEarth
10-28-08, 19:32
Man, that is good stuff! Too bad my Hebrew isnt "good stuff" as well! :)
As far as the RCO ACOG goes...alot of folks here feel that the hash marks to the side of the reticle are lead lines for moving targets or dealing with a good wind but a salty old Marine friend of mine informs me that when a Marine is using his ACOG to observe a target for artilliry strikes or hits from CAS they use the hash marks and call for an"FFE" or an "adjust fire" (just like when one is using a good pair of military type binos).
There is a person who posts here by the name of Bullit5172 or something like that. From my understanding he works at Trijicon. I would find him on the members list and send him a PM regarding this. If anyone can advise you it will surely be him. Cheers
Yes, for some, that can be good. BTW--I saw a photo of an IDF troop using an ACOG mounted on his Tavor. What, if any, is your opinion of this new bullpup rifle?
Ergonomically - it's great. It's built such that you enter right into the proper combat firing position. I
I have very little firing experience with the Tavor - it's currently only found in one infanty brigade out of the six major mandatory-service brigades - and it's my only experience with a bullpup. I don't know about speed in switching magazines - but I guess with practice it's the same speed. It seemed to me also that the weight was unevenly distributed for carry it around on the sling - someone one things of in a country where combat soldiers carry their rifle home with them and pretty much attached to it 24/7. The bullpup design obiously allows it the accuracy of a long barrel with a short profile that makes it great for urban cqb. It's also very modular - , having several built-in picatinny rails - for an american soldier, who receives the m16a4 with the rail handguards it might not be so new, but... I found it very comfortable to shoot on the range, your hands naturally grasp in all the right places. However, the fact that its stock (butt?) is fixed-length and the entire weapon is cannot be collapsed at all as can the short m16 or the m4, , I think will make the weapon difficult to use when wearing ceramic armor and a full combat vest, unless one has particularly long arms. It also has built in BUIS, is supposed to be easier to clean, and much less prone to jams (perhaps related)
In the context of Israeli soldiers, it's good because of the equipment one automatically gets with it. New inductees in the infantry usually will go about half a year with just iron sights, and then usually finish out the rest of their 3 year service (unless they're a designated marksman) with a meprolite reflex sight. The MARS ITL sight, (wonderful in my opinion) is generally reserved for commanders, senior soldiers within a half-year of their release, or the special units. However, the MARS is issued to basic trainees who receive the Tavor with the weapon and it stays with them until the end of their service - there is a special MARS version built especially for the Tavor, and in general more quality optics are issued with it. It can also be easily converted for lefties..
I also support that Israel would use an Israeli weapon in its military - the way that it's appropriate that the US armed forces should use american products insofar as possible. But it's also for another reason - the American equipment that is purchased by Israel or sent there (except for the special forces and elite units) is usually of a certain second-grade quality. A lot of the m16s and m4s are a bit of a chop job, different barrels lengths, it's common to see an m4 upper reciever with an m16 lower receiver (not that that affects performance), ACOGs that no longer glow at night or glow very lightly, reflex sights with a fiber optic beat up badly, ) - because in different periods I guess because of agreements between the two countries they just received whatever America choose to give, weapons that would not necessarly be used in the US. Also, due to the limited budget at the IDF's disposal, weapons that in the US would perhaps be taken out of circulation are kept in use, because there aren't any to spare, so there's a lot of wear on many of them, and a lot of mixed parts (m4 parts with some m4 some other)... anyway.. The Tavors are of homogenous quality and make, and made well because of the government supervision of its manufacture.
Man, that is good stuff! Too bad my Hebrew isnt "good stuff" as well! :)
As far as the RCO ACOG goes...alot of folks here feel that the hash marks to the side of the reticle are lead lines for moving targets or dealing with a good wind but a salty old Marine friend of mine informs me that when a Marine is using his ACOG to observe a target for artilliry strikes or hits from CAS they use the hash marks and call for an"FFE" or an "adjust fire" (just like when one is using a good pair of military type binos).
There is a person who posts here by the name of Bullit5172 or something like that. From my understanding he works at Trijicon. I would find him on the members list and send him a PM regarding this. If anyone can advise you it will surely be him. Cheers
Well... studying can always turn something into 'good stuff' if you want to learn :) The Hebrew writing there just reads "first crosshair", "second crosshair" - it's the lower part of a chart on the same page which lists the difference in cm. between point of aim and the bullet trajectory on the m16, and just notes that t 400 and 500 meters you aim with the the crosshair labeled "4" and the one below it, respectively, for those distances.
I'll try to find him - I'd really like to find the answer to these questions, especially before I make a purchase as these are things I'd need to bring into use and the scopes are a significant investment.
LettersFromEarth
10-28-08, 20:01
Well... studying can always turn something into 'good stuff' if you want to learn :) The Hebrew writing there just reads "first crosshair", "second crosshair" - it's the lower part of a chart on the same page which lists the difference in cm. between point of aim and the bullet trajectory on the m16, and just notes that t 400 and 500 meters you aim with the the crosshair labeled "4" and the one below it, respectively, for those distances.
I'll try to find him - I'd really like to find the answer to these questions, especially before I make a purchase as these are things I'd need to bring into use and the scopes are a significant investment.
Wonderful. BTW--what will you be mounting an optic on anyway? Im going to go out on a limb and guess its NOT going to be a Tavor.:D
ALso, aside from the NSN most of my ACOG time has been on a friends TA33. Wonderful little optic and hands down my fave of all the types Ive shot with. Dont write it off for being "just three power". Get some time in on it and I think you'll agree thats its one groovy bit of glass.
As for learning Hebrew... Man, my German went all to hell within a short time of returning to the States and my Spanish is is trying to keep its home in my brain now! :) Hebrew (and Arabic) are next on my list to learn, though.
'td be a safe limb to go out on :). Not that I'd refuse if I could get my hands on one. I'd be mounting it on an M4.
Wrote several different people bout the reticle and whether that type of range estimation with the side hashes that allowed for head length and profile as well is found in any available model... no one knows... must've been something only in the trijicons there
LettersFromEarth
10-28-08, 20:58
If you havent been advised to LaRue Tactical yet please let me be the first. LaRue Tactical is one outstanding company as far as their products go. When it comes time for you to mount some glass please look into LT as they most likely will have a mount that will fit your needs. Heck, you can even get the optic through them in one of their "combo" deals. Good stuff indeed.
Also, some folks here are into mounts from ADM. I cant say anything about them as I have ZERO time with them but if for any reason LT doesnt fit your needs maybe ADM will. C4IGrant over at G & R Tactical can do right by you as well. He posts here from time to time and seems like a stand up kinda guy. I've never delt with him but I wouldnt have a problem doing so after reading his past posts.
Apparently the reticles I posted are only on scopes that that were sold to the Israeli Military and are not available for sale. (the exceedingly helpful manger of a webstore I am to purchase a acog from, militarywarfighter.com, researched the matter and returned me this answer, as well as prompt answers on all my other questions). Sucks. I don't understand how a designated marksman scope can be built to estimate range based only on full front or back-on shoulder width, basically ruins the really hurts the DM function as providing range and recon information with scope to the platoon. Or maybe the US platoon is equipped with electronic rangefinder, dunno..?
LettersFromEarth
10-29-08, 15:49
...Or maybe the US platoon is equipped with electronic rangefinder, dunno..?
Some of us are;)
Check out Leupolds SPR reticle (Mark 4 MRT 1.5-5X20). I think it is more in keeping with the reticles you are used to. Cheers.
LettersFromEarth
10-29-08, 16:03
How might this work for you?
I recently got into the market of purchasing a $700 - $900 optic for a private security job serving as a DM, and I was torn between the TA01NSN and the TA31F/RCO... I finally chose the TA01NSN, because I felt that the crosshairs would be much more precise for long range shots than the chevron would be, and I prefer the amber ill. The amber, IMO, seems to be easier to distinguish on various backgrounds.
As far as the rest of the ranging tree in the dark, well, I guess that really depends on how dark it is. The other night, I was watching my grandmother's corn field for deer in the middle of the night, and it was about a 3/4 moon, and my entire reticle was extremely easy to see, due to the Triji's excellent glass and light transmission, however, after reading your post, I will go back out and see how it appears in extreme low light conditions.
After all, if it's dark, and you need to engage a target past 300m (the maximum illuminated part of the NSN's reticle), chances are you're going to have trouble seeing the target in the first place with a 4x optic - and God forbid you need to identify a specific target at that range in the dark. But, I guess it would be nice if the entire tree was ill. all the way to 600m...
As for the back up irons, personally, the first thing I done when I received my ACOG was remove the rear ghost ring. I thought it looked bad, and covered too much of what I was looking at if I were viewing something over top of my weapon. The front illuminated sight is enough for point and shoot CQB, using the ghost ring with it would seem too slow, IMO. Currently, I have a mini red dot sight mounted in it's place, so that's working quite well.
If I had it all to do over, I might have looked a bit more at the TA11's, but I don't at all feel like I should have gotten a TA31. Good luck!
Thanks for the info, guys.
I've noticed that the TA01 has two small ovals or circles at the bottom of the sight - does anyone know if this has a particular MOA value?
Battl3fr0nt
10-30-08, 07:10
On the miltary acog's the chevron is lit and so is the line under it. The TA31F and TA31RCO models are what the army and mc use. I find the acog is very good for range finding at night out to 300m. The ta33 acogs are ok but they are not as fast due to the very narrow FOV. I also find I can get a faster cheek weld with the TA31's since there is no guesswork with the eye releif some of you will not get that but most heavy users of the 4x model acog will know what I'm talking about. But yeah imo the 4x model with the chevron is best fot speed and fast pace target shooting.
On the miltary acog's the chevron is lit and so is the line under it. The TA31F and TA31RCO models are what the army and mc use. I find the acog is very good for range finding at night out to 300m. The ta33 acogs are ok but they are not as fast due to the very narrow FOV. I also find I can get a faster cheek weld with the TA31's since there is no guesswork with the eye releif some of you will not get that but most heavy users of the 4x model acog will know what I'm talking about. But yeah imo the 4x model with the chevron is best fot speed and fast pace target shooting.
In the chevron model can you only estimate range by shoulder width of a target who is fully facing you, or is there also a method for measuring a figure in profile (targets faced to the side from you) or by head length (for partially exposed or close targets, and also it's a more constant value than shoulder width)...?
This thread has got me thinking as well - on my TA01-NSN's reticle, does anyone have a diagram or anything showing the distance between stadia lines, whether in mils or MOA? Perhaps these could be used for better range estimation than just using the pre-determined marks that are supposedly set for 62gr. 14.5" M4... I shoot 69gr. 16", so obviously, the BDC marks won't be dead on for me, but if I knew that ,perhaps, the distance between the 3 and 400m marks were equivalent to 3.5 mils (example only), or whatever, something more efficient could be devised. When I bought mine, I was going to set up large targets every 50m all the way out to 600m and just experiment to see how my load works in comparison to the BDC marks, and then memorize the new data myself, or tape a come up card on my stock or something..
LettersFromEarth
10-30-08, 13:03
In the chevron model can you only estimate range by shoulder width of a target who is fully facing you, or is there also a method for measuring a figure in profile (targets faced to the side from you) or by head length (for partially exposed or close targets, and also it's a more constant value than shoulder width)...?
If you want an ACOG you might have to just live with the fact that Trijicon didnt set it up that way for the North American market. You just have to glass targets /objects of a known size and come up with something that works for you.
You may also wish to consider the IOR 3x25 QR-TS. It has mil lines for ranging based on height/size or it also offers the choice to range a targets head by using small "donuts" located to either side of the mil tree.
Good luck, sir.
LettersFromEarth
10-30-08, 13:26
This thread has got me thinking as well - on my TA01-NSN's reticle, does anyone have a diagram or anything showing the distance between stadia lines, whether in mils or MOA? Perhaps these could be used for better range estimation than just using the pre-determined marks that are supposedly set for 62gr. 14.5" M4... I shoot 69gr. 16", so obviously, the BDC marks won't be dead on for me, but if I knew that ,perhaps, the distance between the 3 and 400m marks were equivalent to 3.5 mils (example only), or whatever, something more efficient could be devised. When I bought mine, I was going to set up large targets every 50m all the way out to 600m and just experiment to see how my load works in comparison to the BDC marks, and then memorize the new data myself, or tape a come up card on my stock or something..
I think you and the OP are starting to find out what some squadrons within 7th Cav have learned as well. As I understand it they loved the ACOG for their DMs they started "augmenting" the use of the Trijicon with Leupold Mark 4 MRT's (Im not sure of the power range but I will guess its he the 1.5-5x20).
It is also my understanding that Trijicon will be coming out with a
1-4 AccuPoint with a 30mm tube and a "trick" reticle of some sort(Not sure when we shall see that but Bullit confirmed this over on TOS.) that might be worth waiting for. Take care.
If you want an ACOG you might have to just live with the fact that Trijicon didnt set it up that way for the North American market. You just have to glass targets /objects of a known size and come up with something that works for you.
You may also wish to consider the IOR 3x25 QR-TS. It has mil lines for ranging based on height/size or it also offers the choice to range a targets head by using small "donuts" located to either side of the mil tree.
Good luck, sir.
The thing is, for the job I'm going to be doing, there's a certain uniformity of equipment that must be stuck to and the list of scopes and equipment that can be used is a fairly limited one, due to the combined work we'll be doing.
I guess you're right bout just accepting the limitation of the american-available recticle. :)
The thing is, for the job I'm going to be doing, there's a certain uniformity of equipment that must be stuck to and the list of scopes and equipment that can be used is a fairly limited one, due to the combined work we'll be doing.
In addition, though, upon further research I found out that the distance in the t31RCO hash marks is 5 mils each small one, and 10 mils each large from each other. In addition, the distance from the BDC to the first hash mark is 5 mil.
I also just found out that one of my friends had actually gone ahead and done the work to reverse-engineer out the mil values of lines of the Israeli ta01. (shame that the scope's not for sale anywhere), which is relevant still for the most part to the american crosshair acogs.
http://photos-b.ak.fbcdn.net/photos-ak-snc1/v371/175/26/544066116/n544066116_1977097_1842.jpg
you may have to enlarge it to read the small print of the chart,but by each line one there is a mil value listed.
Feel free to mail me if you have any other questions (like the tavor one) that I can help you with, be glad to, and thanks for the help.
LettersFromEarth
10-31-08, 10:59
Man... HOW the heck do all you posters here seem to get all the highspeed jobs?!?! :) BTW--Good pic on the MIL values of the ACOG. Im going to print it off and use it as a training aid for our DMs. We have been asking like minded questions and its nice to know we will not have to kick around the same sand on this.
You state that you folks have a short list of equipment to choose from. What are some of the other choices (optics) that you may consider?
Anyway, I must be going (Gotta get the kids ready for Halloween tonight) but I'll be lurking around the site throughout the day. Take care.
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