Optics Test

13 June 2001
By Kevin of the GWN

Trijicon Reflex RX01NSN
C-More Colt Tactical Sight
Aimpoint Comp XD-M
Trijicon ACOG TA01-NSN
Colt Carry Handle

CFB Petawawa (circa 1990) - with the C7 in the first few years of issue
CFB Petawawa (circa 1990) - with the C7 in the first few years of issue

Some 11 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.  The advent of the A2 sights was a leap forward for the shooter.  The 300m zero could be kept, but the shooter also had a BDC to adjust to 800m.  The CF, however, saw fit to adopt the C7 with the older A1 sight.

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.

I have never been one to accept another's word for anything - especially when they are so-called experts.  My partner and I have hoarded a couple of each of the sights below in order to demonstrate these to a large city LE agency for use on Colt M4A1 carbines.  Due perhaps to my military background, I also decided to take them out and abuse them in an as-issued format for the SF/Airborne/Light Infantry soldier.

The Firearms tested upon were Colt Law Enforcement Carbines with Colt 1:7" twist, 14.5" barrels - one of which was the new M4 heavy barrel (very nice).  Both were equipped with the KAC RAS.  Note the vertical cuts in the M4HB to permit mounting of the M203.

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.  One thing I noticed is that the sights could all be picked up using NV - the tritium powered ones as well (big glow).  From the front it was harder, but still possible.

Trijicon Reflex RX01NSN

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 “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. uracy 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.

The light gathering face was, in fact, shiny, and I do not like that trait in a field duty sight.  Mike Tac reminded me of this, so I went out and, sure enough, light glints off the sight.  This glint/reflection is especially troubling when the polarizing filter is removed.  The entire face of the sight shines.  The polarizing filter caused more headaches, as it is exceptionally dark and cannot be adjusted to a neutral setting (just less dark).  That one niggling issue bothered me, but I kept the polarizing shield on to cut down on the reflection from the fiber optic window.  And did I say No Batteries?

If I were to take this sight into a rather hazardous area, I would spray paint the front around the polarizing filter and say to hell with the added light, let the tritium do it for me!  While I have no real jungle experience (can't say that I really want any either), this sight would be my choice (with backup iron).  No nasty electronics to corrode and a nice, fast dot.  The RX01NSN, in my opinion, is a good sight that can be modified easily to be great (paint the front screen).  My partner wants to trade his Aimpoint for my ‘extra' Reflex, so some people really do like it.

C-More Colt Tactical Sight

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.  “Oh! Please, I need to replace my batteries.  Just one minute while I remove my sight."  A big Kevin of the GWN 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 XD-M

Since the US Army adopted this unit (80,000 orders), I was expecting a large, bulky, monstrous tube.  However, the Aimpoint is quite compact and very handy.  I like the GG&G cantilever mount, and the extra battery compartment is nice (especially for those who go out on a call and turn the sight on only to see nothing happen).  And, the mount puts the Aimpoint right in line for the PVS-14.

The corded weather caps for the windage and elevation adjustments where also a handy feature (I wish the M3A had them).  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.

Perhaps the best plus is that this sight has excellent compatibility with the PVS-14, both head-mounted and weapon-mounted.  This set-up is ideal; it makes the M4 a great nighttime gun with the addition of a suppressor (I wish Canada had personal ownership).

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.  For this reason alone I would be hesitant to place it on a general-use combat weapon.  One could always raise the irons and turn off the sight, but I know I'd forget (KISS). The flip caps on the scope caused some troubles with using both the PVS-14, and the KAC RAS mounted M203 leaf sight, but if I were going in harm's way I'd sort that out beforehand.

Once I mounted the M203 I noticed that the Leaf Sight is unusable because the GG&G cantilever is mounted so far forward.  This is no big deal, though.  All that one must do if mounting the M203 is move the mount back 3 notches on the rail.  This does not seem to affect speed of acquisition or zeroing.

In close country or FIBUA ops you would have a hard time prying this sight off my gun.  If it were a really long patrol I might pick the Reflex just because I hate batteries.


This is the battle sight for the Canadian Army.  It is mounted onto the C7A1 and C9A1 (M249) (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 did not subscribe to) eliminate the problem of zero loss and other mount-related problems.  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 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.  Some rifle teams have even gone as far as expoxying the mount to the sight after establishing a 300m zero, or paying out of their own pockets to have the sights upgraded to 4th gen specs (see Andy Webber of Armament Technology, as he is the North American Distributor for civilian sales for Hughes-Leitz).

The Elcan is not compatible with any of the typical flip-up sights.  It is too long and needs to be mounted near the rear of the receiver.  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 ACOG TA01-NSN

This was by far the most rugged of all the optics 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.  This scope has great return-to-zero qualities when remounted, which says a bundle about the manufacturing tolerances.  The ACOG has a battle sight back-up on top (handy for close range work), the front post of which has a tritium dot for night/low light situations.

As far as low light work goes, the center of the crosshair glows white at night and provides great contrast for aiming.  However, I would suggest that the white reticle must degrade one's night vision out of unaided eyes - at least, it would degrade mine.  You may place the PVS-14 ahead of the NSN, but in that way the 4x NSN magnifies any imperfections of the NV.  Now, on the PVS-14 this is relatively minor, but it really sucks for those w/o 4th gen night vision optics.

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 (and combat does seem to do that).

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 ACOG is also compatible with the M203 leaf sight.

The crosshair is very ungainly to work with in close quarter battle because it takes too much time to pick up.  For automatic fire, 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.

Colt Carry Handle

I included the carry handle as a base line for the tests partially because I am still prejudiced toward iron for extended field use.  While the sight radius on the M4 does not lend itself to extremely accurate iron-sight shooting, it is still quite effective at combat ranges.  The iron sights are virtually indestructible, though the low light usefulness is limited.  While not as fast as the red dots or as precise as the ELCAN or ACOG, the iron is a nice compromise.  If price is an issue, it is the best option to go with since you can always upgrade later.  Also, iron sights are, IMHO, the only way to properly teach the fundamentals of rifle marksmanship.  For strenuous activities like jumping or mountain ops, the carry handle is my first choice.  Artic operations are best with iron as well (frosty lens, and who needs to magnify light off the snow?).  The other advantage of the irons is that the Quadrant sight for the M203 clips right onto the carry handle.  This provides a better aiming system than the leaf.  I am surprised that no one (Knight's) has brought out a rail-mounted quadrant.


I am still left with some questions in my head.  Is there a best of the breed?  No!  The decision is too dependent upon what you want out of the sights.  I am currently using the TA01NSN ACOG on my M4 for service rifle competitions.  I am still unsure of it in a GP battle scenario, but the flip-up MAD rear gives some added security.

As far as CQB/entry goes, the red dots are the winners - and my choice would be the Aimpoint.  Aside from battery issues, it does everything that could be asked of it.  The Reflex comes in second to the Aimpoint, and if batteries are a real concern, then a shade ahead of the Aimpoint - especially since you never have to turn it on or off.

As for the ELCAN, I still have some issues with its mount (even in its 4th gen rendition), but it is probably the best GP combat sight on the market today.  If you have a plethora of sights to grab out of the golf bag, then you can tailor-mate the sight to the tactical scenario (provided you have a chance to re-zero after re-mounting).

As far as LE ERT duty goes, I think I like the Reflex the best.  The lack of batteries and the great FOV were what clinched it for me.  If the unit had NV for the entry units, then I think the Aimpoint is better, though both do work.  My rationale is that I have seen LE duty guns show up with N/S batteries.

The Reflex is also my personal choice for a patrol carbine in an urban department, and the C79 on a 20" M16 for rural usage (although departments in rural areas might want more reach than the 5.56mm cartridge).

For perimeter use, I think the TA01NSN is the best choice (with 14.5" M4).  If the perimeter unit needs to fire, the ACOG gives an added bit of precision.

As far as bang for the buck goes, the carry handle can do the most with the least.  I must stress that I feel strongly about the necessity of having back-up irons for any optical platform.

What am I doing?  Well, I am keeping the Aimpoint to use with my PVS-14 and for any MOUNT/FIBUA roles; the ACOG I am keeping as my GP sight.  I'll use both sights with the GG&G MAD.  I still have the Carry handle just because, and for NRA service rifle matches were they don't let Canadians use our optics.

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