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Posted: 8/13/2003 7:12:24 PM EDT
Is there a reason that Trijicon makes the 4X Acogs and 3X compact with such a short eye relief. My NSN has "bit" me more times than I can say in Stress shooting in 3-gun and in Training with my unit. I have a TA11 (3.5X) also and I just dont understand why it and the 1.5X and 2X Compact ACOGS have excellant eye relief , but the 3X Compact goes back to the 1.4" and the 4X goes to the 1.5"
WHY?
Also We wear Goggles alot and this sucks when using the NSN, I cant understand why they do this?
I have also read that the TA31s have 1.5" as well but many of the pics I see show people with way more than that,an older pic of new-arguy comes to mind. I dont know, I guess I just dont understand why all the sights cant have the longer eye relief it would solve many many problems IMHO>
can anyone explain this?
thanks in advance
Im ready to absorb the knowledge, HIT ME
(but not with the new 6.8x43 , just kidding) hahaha
cp
Link Posted: 8/13/2003 8:57:25 PM EDT
4X ACOGs are more generous than the 1.5" they list. You can easily use them while maintaining perfect eye relief at 2" or slightly more.
Link Posted: 8/13/2003 9:44:32 PM EDT
I've found with the Compact ACOG 3x that it works best when all the way back on the receiver (which means you'll have to put any BUIS in front of the scope). This is fine for the A1 stock, and will probably best for the A2 stock as well. However if you have a telestock then you can put the compact ACOG in front of the BUIS (specifically an ARMS #40) if you have the stock set to the 2nd positon (of a 4 position stock). Say the stock is set around 8.5" long.
Link Posted: 8/14/2003 6:45:38 AM EDT
I'd also like to know [b]why[/b] the eye relief is so short if Trijicon makes it longer on other scopes!?!
Link Posted: 8/14/2003 9:29:55 AM EDT
The answer is simple. Trijicon designed the ACOG for the M16 family. While you get the most eye relief distance with a shorty, because of varying stock adjustment, the ACOG on the M16 shoulders well with even the full A2 stock. Just like learning the nose to charging handle position you learn in BRM the same applies to using the ACOG. Locate the proper eye relief position and hold the weapon steady into your shoulder. It's the loose hold position where you get into trouble. Some like a cheek piece to aliviate this dilema.
Link Posted: 8/15/2003 7:50:54 PM EDT
The solution is pretty simple - get yourself a drill bit! [img]http://photos.ar15.com/ImageGallery/Attachments/DownloadAttach.asp?iImageUnq=14782[/img] Just don't drill so far aft that you hit the sloped curved portion of the inside of the carry handle. I gained about an inch this way. The iron sights are limited in elevation to 400 meters [rolleyes] due to hitting the bottom of the scope. Flipping the aperture is also impossile to due without a tool but neither of these bothers me - I don't plan on shooting 500 yards distant targets with the irons when I have the ACOG.
Link Posted: 8/16/2003 5:27:21 AM EDT
Welcome to laymans optics 101... Eye relief, objective lens diameter, field of veiw, and magnification are all tied closely together. Using the mini ACOG as an example, given it's dimentionally the same as the 1.5 and 2x scopes, by going to 3x you WILL loose eye relief (and FOV). The TA11 is demensionally larger than the TA31 so it can maintain it's magnification and still have decent eye relief.
Link Posted: 8/16/2003 7:17:46 AM EDT
[Last Edit: 8/16/2003 7:18:36 AM EDT by eaglecp]
Thanks for all the feed back guys. I dont think Im explaining it right though. I have no problem with the short eye relief in a "perfect world" shooting position, at the range for instance, or If in a "hide" for an extended period of time. But when using Goggles or in radid fire situations when you can always get a good cheek weld or your Body armour is in the way that I have a problem. What I can understand is somewhat related to ipschosier1's comment on dimentions of the ACOG the Compacts. all Power units are dimentionally pretty much the same. Why is there such a difference in the eye releif between the 2X and 3X or the 1.5X24 and 3X24. Now if you go to the full size ACOGs you have the 3.5X going back to a long eye relief and and then the 4X goes back short, I just dont see why a 1/2X difference can justfy going to such a short eye relief. I love the 4X units but when you get "BIT" time and time again it gets to be annoying as hell especially knowing how much these darn things cost. It just kind of bugs me and I know Trijicon has to ahve a clue about the short eye relief on the 4X's because I here more complaints about it on this board and from other Soldiers/ friends of mine than any other complaints, I cant believe with all the Technology involved that this cant be corrected. cp
Link Posted: 8/16/2003 9:05:21 AM EDT
Originally Posted By eaglecp: Now if you go to the full size ACOGs you have the 3.5X going back to a long eye relief and and then the 4X goes back short, I just dont see why a 1/2X difference can justfy going to such a short eye relief.
View Quote
My guess is that the TA11's long eye relief is closely related to it's larger size. The TA31 and TA01NSN are much more compact. BTW, I agree completely that the short eye relief scopes are far from optimal for practical shooting.
Link Posted: 8/16/2003 12:17:16 PM EDT
Entry guys dot.Rear guard/perimeter acog.Perfect match,fixes all shortcomings.
Link Posted: 8/16/2003 1:18:33 PM EDT
girard Thank you but.......... What? could you please throw me a bone, Im not really following your post brother, hahahahaha I see "fixes all short comings" and am intrigued. Is this a Modification of some sort? cp
Link Posted: 8/16/2003 2:46:26 PM EDT
I think he's saying the door kickers get red dot optics. Everyone else gets an ACOG.
Link Posted: 8/16/2003 5:51:10 PM EDT
Or have both with a Docter otic on your acog.
Link Posted: 8/18/2003 8:18:36 AM EDT
The main issue here is not power vs eye relief. The issue is field of view vs eye relief. The TA31 has a larger filed of view AND greater magnification in a smaller unit. The only thing that can be sacrificed is the eye relief. The 3X compacts and 4X ACOGs could easily have been made with greater eye relief but they would have abysmal FOVs. I still think the ideal optic would be between the TA31 and TA11 in both size and specs. The TA11 is much easier to use in less than ideal conditions but its a bit large and has almost too much eye relief unless mounted a bit forward of the rear sight.
Link Posted: 8/18/2003 10:07:56 AM EDT
DevL Thats Exactly what Im saying or asking, something between the TA31s and TA11. I personnaly would gladly give up the small difference in FOV between the Ta11 and TA31 for the greater eye relief. Basically the TA31 size with the the TA11 Eye relief. The key here is this scope is designed to be shot in LESS than ideal situations and the extended eye relief would be an excellant advantage. But I think it will be awhile for Trjicon to start considering this because they still dont seam to be able to launch the whole Tri-power thing. thanks guys chuck
Link Posted: 8/18/2003 11:52:55 AM EDT
The 7 degree field-of-view was a SOPMOD requirement for the day telescopic sight and I believe it is also a requirement for th ECOS-C and ECOS-SPR sights designed to replace the ACOG.
Link Posted: 8/18/2003 12:51:31 PM EDT
[Last Edit: 8/18/2003 12:52:53 PM EDT by eaglecp]
B_R The ECOS and ECOS SPR scopes? Replace ACOG? What are those or is there a link to read up on them, Im assuming they havent been released yet or there would be more buzz on this board about them, is this correct? What can you tell me/us about them? does the 7 degree FOV requirement mean that they will have the same short eye relief? chuck
Link Posted: 8/18/2003 1:20:56 PM EDT
[Last Edit: 8/18/2003 1:39:16 PM EDT by Bartholomew_Roberts]
The ECOS-C and ECOS-SPR are just concepts right now. The SOPMOD project is soliciting a new sight and the project acronym for it is ECOS (Enhanced Combat Optical Sight). For example, the Aimpoint M2 was designated ECOS-N initially.
This RFI is to explore industry ability to correct the currently existing operational shortfall of combat optics. Current optics provide Close Quarters Battle (CQB) capability or the ability to improve target-hit probability at longer ranges, but not both. The ECOS will combine those capabilities in one optic. The SOPMOD Program is not seeking alternate sources for the current ACOG 4X (NSN 1240-01-412-6608) or ACOG Reflex sights (NSN 1240-01-435-1916), rather is interested in sources of COTS/NDI versatile, multi-function day optics with illuminated reticles for limited night use. It is desired that the ECOS also incorporate removable Anti-Reflection Devices (ARD) and threat Laser Protection Devices (LPD) to protect the shooter, and electro-optic systems from threat laser damage and laser optical detection. Two types or variants of the ECOS are sought. The first type, ECOS-C, is optimized for use on the M4 Carbine and provides a balance between CQB and mid-range aiming capability. ECOS-C will provide CQB capability, utilizing the illuminated reticle on unity or near-unity power (1x) as a reflex-type sight and will also provide magnification for enhanced target acquisition/identification. ECOS-C must attach to the M4A1 carbine MILSPEC 1913 Standard Rail. ECOS-C must have magnification capability from 1x at the lowest setting to 3-4x at the highest setting. ECOS-C must also have a capability to illuminate the reticle. This can be accomplished by battery power or other method, but must function in complete darkness as well as in bright light that may make low power illumination difficult for the operator to acquire. It is desired that a small dot in the center of the field of view is the only portion of the reticle illuminated. Vendors who have already fielded or are willing to produce an optic with similar capability should include that information in their response. The second variant of the ECOS that is sought will be optimized for long-range target engagement in conjunction with the Special Purpose Receiver (SPR). ECOS-SPR will provide limited CQB capability by utilizing the illuminated reticle on near-unity power (1x-2x) as a reflex-type sight, and will also provide increased magnification for enhanced target acquisition, identification, and engagement. The ECOS-SPR must also attach to the M4A1 carbine MILSPEC 1913 Standard Rail. ECOS-SPR must have magnification capability from 1x-2x at the lowest setting to 6-8x at the highest setting. ECOS-SPR must also have a capability to illuminate the reticle. This can be accomplished by battery power or other method, but must function in complete darkness as well as in bright light that may make low power illumination difficult for the operator to acquire. It is desired that the ECOS-SPR optic incorporate a ballistic cam setting indicator that the operator can view through the scope. Vendors who have already fielded or are willing to produce an optic with the ballistic cam indicator should include that information in their response.
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[url]http://www.fbodaily.com/cbd/archive/2001/02(February)/21-Feb-2001/asol020.htm[/url] I believe the Leupold CQT was an attempt to address this requirement.
Link Posted: 8/18/2003 7:04:40 PM EDT
quote: I believe the Leupold CQT was an attempt to address this requirement.[/quote] B_R Before I finished reading your post I was thinking they were basically explaining the MK4 CQ/T here. I have always like the concept of this sight but think it some things could have been done different. Id be willing to bet there is an improved version in the pipe. ??????? Thanks again for your insight. cp
Link Posted: 8/19/2003 10:22:11 AM EDT
Well we all know that the 1-3X or 1-4X variable power scope will be won by Trijicon right? ;) I didnt realize the BDC would be visable in SPR version while looking through the scope. THat means one could have a front focal plane mil dot reticle and determine range at any setting and dial in the correct range all while looking through the scope... very neat idea. Does anyone make a 1-8X scope right now? Is that even possible?
Link Posted: 8/19/2003 10:43:10 AM EDT
[Last Edit: 8/19/2003 10:43:47 AM EDT by KevinB]
Yes and Yes. The new CF 7.62mm MRS scope has similar spec. A few neat versions are kicking around from the different manufacturers.
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