The US issue a number of sights.
M68 CCO
TA31 and TA31F ACOG - and now the USMC RCO (a TA31F derivative)
I wrote this review for somewhere else but
I took this from a review I wrote pre 9/11 and have made updates where necessary.
Some 16 years after I was issued my first M16-style weapon (the C7), I have owned numerous models and been issued a couple of different ones. I have fallen in love with the flattop uppers. The added versatility that they provide runs roughshod over any perceived lack of durability. The change is most notable from the A1 sights on the original C7 rifles where a 300m zero was used (and the shooter had to hold for variations in range). While the A1's were rugged they required knowledge of bullet drop, and even then the iron sight covered the target at 500m.
With the advent of the C7A1, the flattop, and ELCAN, a new model of infantry combat had been unleashed. The initial ELCAN's sucked, pure and simple. They broke, you could not jump them, and they never held a zero - even from a 16KM Ruckmarch. Range scores went up (provided your scope was not N/S), so the brass was happy, but combat utility went down.
After several fratricide issues on live fire platoon and company attacks, it was noticed that the scope caused nasty tunnel vision. The Brits have noticed this with their SUSAT equipped SA-80's as well. I do not intend to answer the question of whether iron or optic is the best for combat use; my objective is simply to provide a run-down on various sights and how, IMHO, they stack up against each other.
On the red dots, I really like the idea of using both eyes - and if weather or mud/dirt obscures the optic face, you can still see the target and the dot superimposed upon it. They are extremely quick for ambush/CQB. The magnified optics give a lot of power to the lowly infantryman. Now each soldier can search terrain to a far greater range than with the naked eye. For advance to contact, it makes spotting potential enemy positions easier and more likely at a greater range. For target indication, the magnified optic also gives the platoon/section commander a better tool. Both have their uses; some overlap and some do not. [/quote]
Trijicon RX01NSN (Reflex)
The most compact of the sights tested, the Reflex, seems to have a love-it-or-leave-it following. The tritium light source provides battery-free operation and day/night hands-free operability. The yellow dot is easily picked out under most conditions, and the polarizing filter (included, but optional for use) can be tuned to achieve the best contrast against the target background. The 1/2 MOA click adjustments are made with an Allen key (slot would have been preferred), and are very positive.
The mount and sight body are fairly rugged. The hood on the Reflex is larger than most â Å“heads-up" sights, which gives better protection to the fragile lens than the others. The hood also provides great protection from foreign matter on the dot reflective surface. There were some worries that the dot would be visible to the intended target, but that proved to be a non-issue. Accuracy was fairly good: 4" @ 100m out of a Colt M4A1, likely due to the way the dot clearly contrasted against the target and an aiming mark could be repeated.
The Reflex is compatible with both head- and weapon-mounted PVS-14's, giving day/night immediate readiness in either format. The Reflex is also compatible with the various bolt-on iron flip-up sights, and did not compromise their use. The lens cover provides a sacrificial window so that dirt, mud, and such can be quickly wiped off without damage to the lens proper (but you really don't need to). The body in no way obscured the FOV.
No nasty electronics to corrode and a nice, fast dot.
The only problem was the requirement to adjust the polarizing filter repeatedly in different lighting conditions as the dot would ghost against certain backgrounds - this is definitely a concern however it has been liekn to adjusting the brightness of a EOTECH or AIMPOINT, I'm not sure if I buy that - but some who have them still enjoy them (they where pulled out of the SOPMOD kit for the Aimpoint [and in certain unit the EOTECH])
CMORE Tactical
This sight got the greatest amount of WTF? from observers. The idea is quite solid: a red dot heads-up sight with rear A2 irons for back-up and long range. It also has a great LCF (Look Cool Factor). The front lens is a shiny reflective material (can you see me?), as most red dot sights tend to be. However, there are problems in the heads-up lens and its adjustments.
First, the adjustments are WAG - no clicks, just sort of spin-the-wheel-and-see-where-it-goes. Hence, this sight took an unusually long time to zero. Simply put: unacceptable. This may be OK to some IPSC Race Puke, but it is criminal on a duty sight.Second, the hood is made of polymer and is fairly thin. Thus, it provides little impact protection - and the hood piece is the adjustable part! A further question arose from this model having twelve different settings: two for NV and 10 for day/night unaided use. This could be well and good, but since it is formed from the base of a Colt Carry Handle, were does the NV go? There is no room for a weapon mount, and the head-mounted PVS-14 will not allow for any eye relief. Worse yet, despite the fact that the Reflex and Aimpoint had no detectible parallax, the C-More thrives on it: an easy 5" on all sides at 100m. If one looks through the irons (slower, and why the dot?) then one can eliminate the problem; so could several hundred hours of drills on this sight, but why? If I were forced to use this sight, I would epoxy it heavily once zeroed and never take it off the gun.
Last, but not least, the battery compartment is not easy to get to while the sight is mounted. For those who watched Survivors (I think) with Robin Williams, remember the scene were he is out of bullets for one gun and is asking the hitman to let him go back and get the right one? That is the scenario I think of with this sight. â Å“Oh! Please, I need to replace my batteries. Just one minute while I remove my sight." A big KevinB thumbs DOWN. Oh, and I have one to sell. I was purposely tardy with this review in hopes of selling it before the review came out.
This sight could have been very impressive, but was constructed to fail for reasons unknown. I would recommend to C-More that they install a click adjustment for W&A as well as mount the hood in the same manner as the Reflex rather than a front pivot. C-More, if you are listening, you can fix it to be pretty good.
Aimpoint Comp M
Since the US Army adopted this unit (80,000 orders then - now TONS), I was expecting a large, bulky, monstrous tube. However, the Aimpoint is quite compact and very handy. I like the GG&G cantilever mount (now I liek the Larue ), and the extra battery compartment is nice (especially for those who go out and turn the sight on only to see nothing happen). And, the mount can put the Aimpoint right in line for the PVS-14. (no longer a big plus with me)
The corded weather caps for the windage and elevation adjustments where also a handy feature. Numb hands are a little clumsy, and it is very handy to not have to go fishing for things you dropped because your hands are like wood. The 1/2 MOA adjustments were not quite as positive as the Trijicon's, and the labeling confused me (Infantry 031, Duuh!). I found I had to crank the dot setting up near the max to see it during some daylight conditions, but that is why they have multiple settings. Accuracy with the 3 MOA dot was comparable to the Reflex and C-More. [/quote]
The Aimpoint is quite compatible with flip-up rear irons, and makes for a good short- to medium-range sight, but the 3MOA dot precludes its use at ranges much beyond 300m. Due as well to its 1x lack of magnification it is a poor system for tgt detection/discrimination. For this reason alone I would be hesitant to place it on a general-use combat weapon.
The M2 and M3 are refinements in design and I did not think need their own seperate chapter.
C79 Elcan
This is the battle sight for the Canadian Army. It is mounted onto the C7A1 and C9A1 (M249) [now C7A2 and C9A2] (BTW what sort of pinhead puts optics on an area weapon? - plus, the added shaking!). The Elcan has suffered through a long line of teething problems. While the optics (3.4X) are top-notch, the mount has issues. I broke a few during my service with the CF, and once returned with only the mount (the Elcan had departed for parts unknown - and no, I did not steal it!).
The system mounts fairly high because the ballistic cam/range dial on the sight is hinged at the front, where it is windage adjustable in 1 MOA increments. The rear elevation dial is also adjustable in 1 MOA clicks. This rotating hinge gives two points of contact with the second (the range dial) being the weak link. Any rearward impact is transferred right onto the range dial, leaving the scope flopping up and down, only connected by the windage pin. The fourth generation modifications to the mount (which the CF just recently subscribed to C79A2) eliminate the majority of the problem of zero loss and other mount-related problems, or at least delay them longer than the early gens. Even so, I personally feel that the mount is too subject to impacts and not strong enough for the role it is intended.
The optic is a great combination/compromise for both close- and longer-range shooting, though. The tritium triangle on the post is quick to pick up, especially in low light, and yet is still fine enough at the tip to provide a clear aiming reference at longer ranges. The range dial is calibrated(ish) for the C77 (SS109) ball round out of the 20" C7 barrel to 800m. The Elcan is not NV compatible, nor does it have to be (for its intended role). The tritium light source provides a good reference to aim at muzzle flashes, and the scope gathers a great deal of light on its own.
In any field environment, the scope naturally sees its share of the field - causing it to become covered in mud, etc. This has to be removed or the scope is useless; and unlike iron sights where one can simply shake the dirt/mud off, the optics typically have to be washed out.
The Elcan is not really compatible with any of the typical flip-up sights. It is too long and most shooters needs to mount it near the rear of the receiver. (When I used one I pushed it forward and mounted a BIS - but I think I was relatively unique) Diemaco has produced a back-up sight for use on the C7A1 that mounts forward of the ELCAN, but it is constructed with a plastic body that is more flimsy than the C79 itself. I don't see much point in a back-up that, IMHO, will self-destruct long before the sight.
Trijicon TA01NSN
This was by far the most rugged of all the optics then tested. I dropped my M4A1 with ACOG from 6' to the ground, and then went out and took top score shooting the C7 PWT. The crosshair is extremely fine for a combat sight, so it is extremely good for longer-range work. The sight is calibrated for the M855 (SS109) round from the 14.5" M4 barrel. The bullet drop calibrations are right on the crosshair, which leaves no external adjustments for range. Windage and elevation are adjusted with 1/3 MOA clicks, and the adjustments are quite positive and easily made. Weather caps cover the screws when not needed. This forces the shooter to aim off for windage, for better or worse.
As far as low light work goes, the center of the crosshair glows amber/white at night and provides great contrast for aiming. However in certain near dark dusk conditions the amber/white tritium merges with the black reticle and forms a uniform shade of greay the same colour as the surroundings - not good.
The other issue, which it shares with any conventional optic, is inclement weather performance. The optics can become covered in water during rain, obscuring the reticle and target. This does not happen with the dot sights, as one's eyes simply superimpose the dot on the target seen by the other eye. Also, the rear of the optic tends to frost over with ones breath during cold weather ops, especially if one is exerting oneself heavily
Another nice point about the ACOG is that it mates very nicely with an assortment of flip-up rear sights. These cannot be flipped up while the ACOG is attached, but the ACOG can be removed/flung/cursed/etc. if one suffers a catastrophic failure.
The crosshair is very ungainly to work with in close quarter battle because it takes too much time to pick up. For automatic fire, or shooting on the move it is quite distracting to see the crosshair jump about and it is very easily lost while doing this. That is one real issue with the NSN. It would make a really nice perimeter weapon for LE, though.[/quote]
EOTECH 552
We issue the EOTECH 552...
With the 552 are a 500hr battery life from a AA battery - and you can use the Lithium AA's for more and better low temp performance, and 8 hour auto shut off (for those who whine about that - nowhere are you going to leave the sight on one setting for 8 hours while using it) The EO as well has its own built in mount (so you save on cost - I think the Larue mount for it is a good investment but not necessary unless you really need that 1/10 of a sec gain for being a wee bit higher).
FOV is excellent
I think the EO 553 will be the HEAT - it was designed with feedback from CAG shooters in the US, from their issue 552's - Lithium123 batteries, taller and throw lever mount. -- IF it is ever released to the civilian market.
However the EOTECH's are still a CCO with 1x properties - they are good for CQB but lose their edge as distance increases.
Trijicon TA31/TA11 BAC ACOG Series.
Probably the best GP fixed power scopes on the market - CBQ capable due to BAC and yet with magnification and BDC properties to use at range. Same principles as the TA01NSN - but with the Bindon Aimng Concept - using a permanently lit (trituim and fibre optic) reticle for two eyes open aiming as a CCO. Users will notice a POI/POA shift while using them in the BAC mode do to how the brain processes the visual data - exactly how much is dependant upon the individual. The TA31 series replaced the TA01NSN in the SOPMOD package and has been adopted by the US Army and USMC as rifle and carbine optics.
