3/16/07 - Back in 2003/2004, when I first got my Docter Optic mini red dot sight, I mounted it on my LMT MRP as the primary optic. At that time, it wasn't very common to see the MRD (Mini Red Dot) sights used as primary optics on rifles, probably because they hadn't been around for too long, and people didn't trust their durability. The Docter and now discontinued Optima (now manufactured as the J-Point) were used mostly on competition pistols or as backups on rifles on scopes. Then, they found some popularity mounted on ACOGs as close-range optics. When I mounted the Docter on my MRP, I just wanted the smallest red dot sight I could stick on there, and the Docter has worked well for the past 3 years it's been on there. However, there was always the chance it could get damaged as it was unprotected. I was also using the Docter weaver mount on top of an ARMS #17, to get it to the right height. As the mini-dots have grown more popular and common due to their light weight and small size, so have the choices of mounting options. LaRue Tactical has stepped up to the plate and is offering mounts and MRD (Mini Red Dot) packages with their excellent locking lever system, called the LaRue Irondot.

MRD bases - LaRue is offering MRD bases, for those who already own a MRD. The mount incorporates LaRue's adjustable locking lever, just like their other mounts. A bent sheet metal guard protects the sight on both sides and the top (the only one that protects the MRD on all sides). The top isn't covered completely to allow the plastic cover that comes with the sights to be removed. There are holes in the guard that allow access to the windage adjustment screw on the side. While it makes the sight look a bit blocky , it's functional and does the job.

The LaRue MRD bases are available to fit the J-Point, Docter, Burris FastFire and Pride-Fowler MRD footprints. The difference between the Docter and FastFire mounts is that the Fast Fire guard has a cutout for access to the on/off switch on the left side.

LaRue Irondots - LaRue offers two MRD/base combinations as their IronDot, using either the Burris FastFire (LT-627-FF), or the Pride-Fowler MRD (LT-625). Both are M4 height. The LT-624 is a Pride-Fowler MRD on a low profile mount. This lower profile mount sets the MRD lower on the rail and does not have the flip-up rear sight. It is not currently available for the FastFire or Docter, only the Pride-Fowler.

LaRue FastFire Irondot LT-627-FF - The Burris FastFire is one of the latest (at the time of this writing) MRDs to hit the market, and also the most reasonably priced (under $200 for the sight alone, $100 less than its competitors). It looks almost identical to the Docter Optic, except that it has an on/off switch on the left side. I really like that feature, as it doesn't depend on the plastic cover to turn the sight on and off. The FastFire can be turned off to save the battery without having the plastic cover on. The FastFire has a 4 MOA dot, a tad larger than the Docter's 3.5 MOA, and I found it to be brighter and just as sharp under the same lighting conditions. The window glass also has less of a bluish tinge to it and I can see no difference in the clarity or distortion between the two. The FastFire has a metal housing, instead of the plastic one like the Optima and J-Point. Like the Docter, the Fast Fire has a light sensor at the front of the body which senses the light level in the direction of the target, and automatically adjusts the brightness of the dot.

The FastFire is installed in the Irondot mount with two screws. The mount has alignment pins on the top surface that interface with holes in the bottom of the optic. This ensures repeatability of the optic when taken on and off to change out the 2032 lithium battery. The integral flip up rear sight eliminates the need to an additonal one on the rifle. However, I elected to leave my rear BUIS on, as I like the sight picture afforded by the thicker/standard aperture. The Irondot flip up rear has the large aperture. There is a spring loaded plunger that contacts the cross-bar and secures the sight in the up and down positions. Windage adjustments are made by loosening the two small phillips screws that attach the sight to the cross-bar, and moving the sight left or right. The holes on the sight as slots. It's an iterative process - you have to check the alignment of the sight, flip it down to loosen the screws and drift it to either side, then flip it up again, as there is no access to the screws in the up position. A recess at the back of the base aids the finger in getting behind the sight to flip it up.

I've always found adjusting MRDs to be a bit of a pain, as they don't have click adjustments. There are two lock screws at the rear of the sight. Those need to be backed off before elevation and windage adjustments can be made. Adjusting the dot itself is easiest if you already have your irons sighted in. Then, you just adjust the dot to co-witness with the irons. If your irons aren't sighted in, I highly recommend a laser bore sighter. My laser bore sighter has saved me a LOT of time and ammo by putting me very close before I even go to the range. Then, only the smallest of adjustments are necessary. I use a laser bore sighter for all my rifle optics and also when changing out handgun sights. Shown below on the far right is the Irondot in comparison to the Eotech and Aimpoint red dots. Its smaller size is obvious.

On both weapons shown above, you can see that the Irondot is a more compact package than either the EoTech and Aimpoint. Another advantage, I feel, over the other sights is that there's a lot less clutter around the window. No flip-open scope caps or knobs, or battery compartments, and less width. No tube to look through. Dot sights are meant to be used shooting with both eyes open, and I find that my eyes have less problems superimposing the dot on the target is there's less occluding the eye looking through the sight. You might remember the old Armson OEG, which you did not look through, and superimposed the dot on the target (same thing as closing the front scope cap on an Aimpoint). Some people just could NOT get used it. I found the Irondot sight picture quick to acquire.

As I mentioned above, I've used an MRD as a primary optic on the MRP for more than 3 years as I wanted the most compact and lightweight dot sight, and it hasn't given up anything in performance to the larger optics. The only thing I can think of is that you have no control over the brightness of the dot as it's automatic (the Pride-Fowler, however, does have a 'maximum brightness' setting on its on/off switch). On the other hand, you're not messing around with knob or buttons to adjust brightness when going from light to darker environments (such as in and out of buildings) as it's all automatic.

The LaRue Irondot offers all the features you'd want for mounting an MRD - puts it at the optimum height for co-witness, protects the optic, incorporates a rear BUIS and last but not least, uses the proven LaRue adjustable locking lever. In my opinion, the only way to go if you're going to run an MRD. Another great combination from LT.

7/22/06 - This is old news now to those that have been paying any more than cursory attention to the firearms industry over the past couple of years - LaRue Tactical in Leander, Texas has garnered the reputatution as the tactical mounting system to get, for professional and civilian users alike. Mark LaRue and his team have developed a strong following, both for their customer service and quality/design of their products. This writeup is long overdue, as I hadn't had the need to replace the existing mounts I'd had for a few years (they worked, but were not optimal), but after a correspondence with Mark LaRue, we agreed that it was time. I chose to update my Aimpoint Comp and Trijicon ACOG mounts.

QD mounts - Now, quick-detachable (or QD) mounts are nothing new in the optics arena. Various mechanisms have been used, like big thumbscrews, Leupold's quick-release mounts, ARMS throw levers, to name a few. Basically, any method that allows the installation and removal of an optic or accessory without the use of tools. When it came to military-specific QD systems, most users were familiar with ARMS throw lever mounts. ARMS throw levers utilize a camming action to lock the mount in place. By closing the throw lever, it pushes a plate against the under part of the rail, locking the mount in place. However, the locking force on the plate by the cam is dependant on the manufacturing tolerances of both the mount and the rail. Because of this variation, you can end up with a mount that's too tight (broken levers) or too loose. The ARMS mounts I've used worked fine for me (civilian use), but I could notice the difference in lever tension right off the bat.

LaRue system - LaRue's locking lever system makes this a non-issue. Each locking lever has a 3/8" adjustment nut. By turning the nut clockwise or counter clockwise slightly with the supplied wrench, the tension of the locking lever is adjusted to fit the rail. The LaRue locking lever is a machined steel part; virtually unbreakable. No worries about having one of these snap off. When the mount is placed on a 1913 rail, the locking lever is rotated so that it's cam surface contacts the underside of the lower half of the side rail. Like any other secure mount, it'll mark the finish on the rail after time, which is unavoidable, and not really an issue.

When I asked Mark what the correct tension should be for the locking levels, he said that they should be adjusted so they're "tough to close and a bitch to open" (in Mark's words). Done correctly, there will be NO fwd-aft movement of the mount and a guarranteed return to zero of the optic. Bear in mind that 'bitch to open' means that you get it as tight as possible without needing a prying device to help unlock a correctly adjusted lever. However, 'tough to close' means different things to different people. Mark has come up with some guidelines. For most applications, adjusting the angle of the locking lever so that it's at 45° when you first feel it make contact with the receiver before tightening it is sufficient. If you don't intend on removing the mount frequently and feel the need for an extra bit of tension on the locking levers, you can go as far as 60°, but no more.

Most of the newer mounts also incorporate the 'lever safety lock', which eliminates accidental opening of the locking lever. An aluminum sleeve slides back and forth on the locking lever, and when locked, engages a groove machined in the mount, preventing the locking lever from being opened.

Switching mounts was simple. The LT150 has four screws that hold the removable ring to the fixed one, which is machined as part of the base. The bottom of the base has two recoil lugs, and a O-ring sealed spare battery compartment (you can still see white grease in the photo above). The compartment cap is easily removed with a coin.

10/11/08 - ACOG RCO Mount - The ACOG RCO QD Mount is designed for Trijicon TA31RCO (Rifle Combat Optic) ACOG scope, which is essentially a TA31 with a special reticle designed for the USMC. There are different variants of the TA31RCO; one of them is for the M4A1 and another for the M16A4. One of the issues with the M16A4 in service with the USMC is the non-collapsible, full length A2 stock. The long length of this stock can cause issues when wearing body armour as the stock is too long to allow proper eye relief with magnified optics. The 4x32 ACOG series of scopes have a relatively short eye relief of 1.5", and require the eye to be quite close to the eyepiece. Most ACOG mounts place the rear of the ACOG approximately in line with the rear of the upper receiver and charging handle. When I'm shooting with my TA01NSN pictured here, I have to shoot nose-to-charging handle with my stock collapsed almost all the way. If I had a standard stock, I would not be able to maintain the proper eye relief and cheek weld unless I moved the ACOG further rear on the receiver rail. The problem with moving the ACOG rearward is the mount would then interfere with the operation of the charging handle. Whenever there's a problem, there's a good chance that LaRue will come up with a solution; and they have, with their ACOG RCO mount.

The LaRue ACOG RCO cantilever mount allows the ACOG to be mounted about 2-1/4" further back on the receiver rail than a standard mount, enabling users with standard stock to get the correct eye relief with the scope. The RCO has a narrow rear section which matches the contour of the rear of the upper receiver, providing unrestricted access to the charging handle.

The RCO mount has one locking lever on the right side (less snag potential on gear for right-handers), with a lever safety lock. I've shown it here side-by-side with the LaRue LT-100 ACOG mount (reviewed immediately above). As usual, the mount comes complete with replacement mounting screws with allen wrench, QD adjustment wrench, vial of blue Locktite and Instructions.

The RCO mount works with all ACOG models. Lacking an ACOG RCO, I mounted my TA01NSN on it. Installation is exactly the same as with the LT-100 ACOG mount; two screws and you're done.

Mounting the ACOG in the rearmost position (pictures on the left, below) means that you cannot have a rear back-up iron sight mounted. I guess you could mount a flip-up BUIS in front of the ACOG and use the large aperture if you really needed to.
The RCO mount can also be used in place of the LT-100 in the standard position, with a BUIS mounted behind/under the ACOG (pictures on the right). I actually prefer the RCO mount to the LT-100 as it has a slightly lower profile.

9/1/06 - SPR-S Mount - The SPR-S mount (LT158) is a one-piece base mount that's basically the same as Larue's SPR/M4 mount, but .090" lower to place the centerline of 34mm rings 1.5" above the rail when it is not necessary for the eyepiece of the optic to clear a rear backup iron sight. With 30mm rings, the scope is centered 1.41" above the rail. For the 1" rings, the centerline is about 1.3" above the rail. The SPR-S also has 10 MOA of slope built in.
Overall length of the mount is 5.85", including the cantilever extension in front. The rings are set forward so that the proper eye relief can be obtained when mounting a scope on an M4 or similar weapon. The base of the mount that grabs the rail is about 4" long.
The rings are split vertically, and bolt to the base from each side with torx-head screws. Both halves are separate, instead of one fixed ring like the Aimpoint mount. Each ring has two threaded inserts, set diagonally opposed. When mounting the scope, the bottom two screws are tightened first, securing the rings to the base. It's an extremely solid and clean-looking setup.
The SPR-S has two locking levers with the rear one incorporating the 'lever safety lock' which prevents accidental opening of the lever. I picked the SPR-S to mount the IOR 1.1-4X scope shown below as it povided just the proper amount of clearance to the FAL para rear sight (see pics below) or the new rail for my M1A that's coming. Also shown is another SPR-S with 1" rings and a 3-9X40mm B&L scope installed in an AR flattop.

Rather than describe the IOR Valdada 1.1-4x26mm CRT (Close Range Tactical) scope here, I'll refer you to a detailed review of an earlier version (with a different reticle) by Scott Powers on snipercountry.com. Manufacturer specifications can be found here.
Scott wrote an article on another of IOR's scopes but with the CQB reticle, which I'll quote in part here as Scott is much more knowledgeable about optics and can explain it better than I (quoted with Scott's permission - thanks Scott):

I haven't experienced the battery drain that Scott mentioned so far, but I'll definitely mention it if I notice it down the road. The red illumination that he mentioned can be seen from the front for quite a distance only if the observer is looking directly down the tube. There is no side signature that I can see. The CRT is a hefty scope at 15.6 oz but still lighter than the Short Dot. It's shown below on a flattop and FAL PARA to illustrate eyepiece clearances with LaRue's SPR-S mount.

9/10/06 - J-Point/Dr Optics Attachment and 1" ring inserts - The J-Point/Dr Optics Attachment (LT137) enables the user to mount a J-Point or Dr Optic mini-red dot sight alongside a scope. This provides a close-quarter optic if a target of opportunity pops up and is too close to use a magnified optic on, if there's no time to dial down the magnification on your scope or if you've got a fixed-power scope like a 10X.
The LT-137 is a platform machined on the side of a LaRue 30mm ring (it's only compatible with LaRue bases). The platform is reversible for the J-Point (or Optima), and the Dr Optic, which have different footprints, and is attached to the ring with two Phillips screws. There are short index posts which interface with the holes in the base of the optics, and help keep the optic aligned and repeatable when removed for battery changes.

The LT-137 can be installed on either side of the scope by just replacing the existing 30mm ring. I installed it here on the SPR-S base, with a 1" diameter tube scope, so I had to use the LT-136 1" ring inserts which convert any LaRue 30mm ring to 1". The LT-137 is installed before putting the optic on, to provide access to the ring screws. The optic just screws on. The mount puts the dot roughly 1.3" above the centerline of the scope, and 0.95" to the left or right of center. The offset should be considered when sighting in the weapon.

I had originally assumed that right handed users would mount it on the left side of the scope, and vice versa for left-handers. So, being a lefty, I mounted it on the right of the scope. To use the dot sight, I shifted my head slightly up and to the right, to get my left eye on it. In doing so, I had to lose my cheek weld. Usable, but didn't feel optimal. I then tried mounting the LT-137 on the left side of the scope. To look through the dot sight, all I had to do was lift up my head slightly, and cant the rifle inboard a bit while still keeping my chin on the stock. I found it to be quicker and more natural feeling, plus I still had a decent cheek weld. Also, by canting the rifle, the dot is above the centerline of the bore. The user should try it both ways and pick the one that suits him.
The attachment can be mounted in the forward or aft position. Again, it's personal preference. When used with the Leupold MK4 (extreme right), I found that the dot sight worked better in the forward position so it wouldn't interfere with the side focus knob. Try it both ways and see which position works better for you.

7/29/07 - The LaRue Tactical LT-649 is a pivoting mount for 30mm magnifiers like the Aimpoint and EOTech 3X magnifiers. Aimpoint and EOTech introduced their 3X magnifiers that mount behind their red dot and holographic sights, which enables those optics to be used at CQB and medium range distances. However, some people felt that the mounts available for the magnifiers were lacking, and asked Team LaRue to come up with something.

A pivot mount is more desirable over a QD mount as you don't have to remove the magnifier from the weapon - you just pivot it out of the line of sight to the side when not in use. LaRue came up with a very rugged and simple design with no knobs or levers to push to pivot the optic out of the way. A 30mm one-piece ring (split at the top), is cross pinned to a 5/16" shaft. This shaft rotates in the base of the mount. There is a cross pin in the shaft, which rests in detents 90° apart. There is a spring between the mount and the front of the ring. When the ring/optic is pulled back and the spring compressed, this allows the cross pin in the shaft to disengage from the detent, and the ring to rotate 90°. The optic then 'snaps' into the detent 90° from the previous one. When mounted with the LaRue locking lever to the left, the optic is pulled back to compress the spring and the optic pivots to the right (for right handed use). For left handed use, the mount can be turned around so that the locking lever is on the right, and the optic then needs to be pushed forward to unlock it from its detent and pivot it to the left.

"Poor-boy" special - Now, the Aimpoint and EOTech 3X magnifiers aren't cheap, and their high price has pretty much been the main complaint about them. For the more monetarily challenged, or value-conscious individuals, LaRue went out and acquired some surplus Hensoldt 2.5X magnifiers with 1" tubes that are a fraction of the cost of the Aimpoint and EOTech magnifiers. Whether the user needs the extra .5X power is up to him to decide. Hensoldt is the well known German maker of quality optics, including the HK scope seen on many of the G3's. Hensoldt is now Carl Zeiss Sport Optics. Mark calls this the "Poor-boy" (PB) special and it's offered until the Hensoldts run out (they have limited quantities).

The Hensoldt has a 1" tube, so the PB comes with a 1" ring insert for the 30mm ring. LaRue had the Hensoldts inspected, the original tank ranging reticle removed, and the optic repurged with nitrogen (to eliminate internal fogging). The magnifier is 4" long and very solidly built. I estimated eye relief to be about 1.5".

In the photos below on the right, I set it up with the mount flipped around so the locking lever is to the right. I tried it the right-handed way, but prefered the magnifier to pivot to the left, out of my field of vision, when shooting left-handed. The only difference is that I have to push the magnifier to pivot it instead of pulling it. One issue with this setup is that the magnifier can interfere with the charging handle latch access, if you're using a Tac-latch. Without a Tac-latch, you can still access the latch the normal two-fingered way. The lefty access issued was solved by using the Badger Ordnance ambidextrous charging handle which allows me to 'sweep' it with the knuckle of my index finger.

I did move the Aimpoint one notch further forward on the flattop than it was, to make room for the pivot mount. I also didn't adjust the locking lever on the pivot mount to close and open with as much tension as I normally do with an optics mount; I adjusted it so that it's snug, but still easily removed. The sliding lever safety lock provides an additional level or security.

The 'Poor-boy' Hensoldt magnifier is crystal clear, and the pivot mount bonehead simple to use. The mount centers the Hensoldt with the Aimpoint tube, when used with the LaRue LT-150 Aimpoint mount. Note that LaRue makes a low version of the pivot mount that places the centerline at 1.535" from the top of the rail for use with the EOTech line. The EOTech, in its stock configuration (without LaRue EOTech mount) sits lower than an Aimpoint, and therefore requires a lower pivot mount to center the magnifier in the window.

At the range, I mounted the Aimpoint and Hensoldt on an LMT MRP. Eye relief with the Hensoldt was just fine shooting NTCH. We were running a bunch of drills that day, using both paper targets and steel. I found that the Hensoldt really helped my get the Aimpoint dot on 8" steel circles at 50 yards. My eyesight isn't that good (and neither is my shooting, for that matter), so the extra 2.5X magnification really made a difference at that distance. I found that my speed for getting shots off went from slow to not-so-slow (I'm a slow guy), so I was personally very impressed with the setup. At closer distances, all the way down to 3-5 yards, the magnifier was easily and quickly pivoted out of the way. A couple other shooters tried it out and were also impressed, especially considering the price of the Hensoldt compared to the Aimpoint 3X magnifier (a difference of more than $350). If you have an Aimpoint, but haven't picked up the 3X magnifier because of the cost, you owe it to yourself to pick up the LaRue Poorboy special while they last. (Note that they are now out of them)

Poorboy on LMT MRP at the range

11/25/07 - Pretty much as soon as Aimpoint released my new favourite sight - their new Aimpoint Micro T-1, LaRue Tactical came out with their QD mounts for the Micro-series of Aimpoint sights. The LaRue Tactical LT-66X fits all Aimpoint Micro sights and comes in two heights - LT-660 (High) and LT-661 (Low).

The Aimpoint Micro sight comes with its own picatinny base, which is keyed to the sight housing to absorb recoil. The base attaches to the bottom of the Micro with four small allen-head screws. The Larue LT-66X mounts have exactly the same interface as the factory base, and installation is as simple as removing the four base screws, and replacing the factory base with the LaRue mount. The LT-661 is slightly higher than the factory base and the LT-660 is about .8" higher than the LT-661. The LT-660 is hollow inside; not a solid block of aluminum, as seen below.

As with all LaRue mounts, the LT-66X is hard anodized with a matte black finish. It has a single adjustable LaRue locking lever with safety lock. The bottom of the 66X has a recoil lug - it's as solid as a mount can get. The Micro can be installed on the LT-66X mounts so that the locking lever is on the left or right side of the rifle. Installing it with the lever on the left makes access to the rotary switch easier, but on the other hand, the locking lever on the right side could also serve to protect the rotary switch from certain impacts as it extends beyond it a bit.

Aimpoint Micro - The Micro was debuted at the 2007 SHOT show and caused quite a buzz. "Micro" is an apt choice for a name as the mini-red dot sight is small; only 2.4" long and 1/6" wide. Rather than go with an open mini red dot design like the Docter or Burris Fastfire, Aimpoint stuck to the tube design, with is inherently stronger and better protects the electronics from the environment.

The Micro T-1 (shown here) is the military-spec'd version of the sight. Civilian versions are the H-1 and R-1, which have no night vision settings and have different environmental specifications from the T-1. The Micro sights are powered by a single 3V Lithium CR2032 coin battery which will last over 5 years of continuous use at position 8 of 12. The battery is stored in the rotary switch, which is rotated to the desired dot brightness. The T-1 has a 4 MOA dot size. Windage and elevation adjustments are done with the adjustment caps. The adjustment caps have two small prongs on top which fit into recesses in the adjustment screws. No tools are needed for zeroing. The T-1 has 12 settings - 4 night vision and 8 daylight with one extra bright.

The LT-660 High mount provides a lower 1/3 co-witness with iron sights on an M4 or AR-15 flat top. It places the center of the Micro at about 1.65" above the picatinny rail.It's shown below in comparison to an Aimpoint M2 in standard LaRue LT-150 mount. As you can see, it's a much smaller package.

The LT-661 Low mount puts the center of the dot about 0.85" above the rail, and is designed to get the sight down low. The bottom of the tube opening is about 0.4" above the rail. The low mount is meant for AKs, shotguns, or ARs with raised top rails like the KAC RASII hump, ARMS SIR, and Vltor CASV-M (shown here). As mounted on the CASV-M (or EL), the LT-661 allows a co-witness of the iron sights, and puts the T-1 at the perfect height for this set up.

LT-660 co-witness

Size comparison with M2

LT-661 on Vltor CAS-VM

On HK93

11/23/10 - Two of the latest mounts for the Aimpoint Micro sights from LaRue Tactical are the Absolute Co-witness Micro Mount LT-751 and the Angled QD LT-724 mount. The LT-751 places the Micro at the correct height above the flat top receiver to center it in the iron sights. The LT-724 puts the Micro at an offset so that it can be mounted in front of a magnified optic, and used by canting the rifle over a few degrees for rapid transition to close-range targets.

The Aimpoint Micro sight comes with its own picatinny base, which is keyed to the sight housing to absorb recoil. The base attaches to the bottom of the Micro with four small allen-head screws. Like the LaRue LT-66X mount featured previously, the LT751 and LT724 mounts have exactly the same interface as the factory base, and installation is as simple as removing the four base screws, and replacing the factory base with the LaRue mount.

Both are machined out of bar-stock aluminum and hard anodized with a matte black finish and have a single adjustable LaRue locking lever with safety lock. They come complete with replacement mounting screws for the Micro (with wrench), a QD adjustment wrench, a vial of blue Loctite and instructions.

Aimpoint Micro Mount LT-751 - The LT-751 was developed by overwhelming demand for a Micro mount that provided an 'absolute co-witness' with the iron sights. The LT-660 mount which was introduced early on has a higher 1/3 co-witness with the irons. In other words, when sighting through the iron sights, they are centered in the lower 1/3 of the Micro's tube. The LT-751 is slightly lower, and centers the irons in the Micro's tube. It is intended for use with folding front and rear iron sights flipped down most of the time, while fixed irons are better used with the taller LT-660.

Rather than the 'box' shape of the LT-660, the LT-751 has a more streamlined and elegant I-beam cross section. The Micro can be installed on the LT-751 so that the locking lever is on the left or right side of the rifle.

The difference in cheek weld between the LT-660 and the LT-751 is very small; it's hardly noticeable swapping between the two. I do like the LT-751 for use with flip-down front and rear sights, but prefer the taller LT-660 if either the front or rear are fixed. But...I really like the sleeker look of the LT-751.

LT-649S - The LT-649S (Short) is a lower height version of the LT-649 pivot mount featured previously with the Hensoldt 2.5x magnifier. The LT-649S was designed to work with any model Aimpoint (except Micro) in the factory mount w/spacer. It will also work with a variety of other mounts and optics. An excellent chart illustrates these combinations. One of the combinations illustrated is the LT-649S with the Aimpoint Micro in the above LT-751 mount. The centerline of the magnifier is slightly higher than that of the Micro, but it's still very usable. The Aimpoint 3x magnifier has a 30mm tube instead of the 1" tube of the Hensoldt, and the offset will be even less noticeable.

Other than the height, the LT-649S is exactly the same as the LT-649T. It allows the user to just pivot the magnifier out of the line of sight to the side when not in use instead of having to remove it completely. A 30mm one-piece ring (split at the top), is cross pinned to a 5/16" shaft. This shaft rotates in the base of the mount. There is a cross pin in the shaft, which rests in detents 90° apart. There is a spring between the mount and the front of the ring. When the ring/optic is pulled back and the spring compressed, this allows the cross pin in the shaft to disengage from the detent, and the ring to rotate 90°. The optic then 'snaps' into the detent 90° from the previous one. When mounted with the LaRue locking lever to the left, the optic is pulled back to compress the spring and the optic pivots to the right (for right handed use). For left handed use as shown below, the mount can be turned around so that the locking lever is on the right, and the optic then needs to be pushed forward to unlock it from its detent and pivot it to the left.

LT-724 Angled QD mount - The LT-724 is designed to fit on the upper receiver, in front of a Trijicon ACOG, or on a stable railed handguard in front of a magnified scope. The LT-724 can be purchased alone or in combo form with a T-1 or H-1.

The purpose of the LT-724 is to provide a secondary close-range/CQB optic when using a magnified main optic for engagement of close-range targets. While magnified optics (that do not go down to 2 or 1x) can be used to engage close targets, they're generally slower and not as efficient as a non-magnified red dot for anything under 50 yards. The LT-724 places an Aimpoint Micro at the 11 or 1 o'clock position; on either side of the main optic. It consists of a base with a single locking lever and an offset extension mount for the Micro. I wouldn't mind seeing a picatinny version of this mount so that other optics such as mini-red dots could be mounted as well. The mount can be used for left or right side mounting of the Micro.

The LT-724 will fit in front of an ACOG on a standard upper receiver, but will have to be mounted on a railed handguard if a longer scope is used. Transition from the main optic to the offset Micro only requires a slight cant of the rifle, without a change in cheek weld on the rifle stock. It's very quick and doesn't require you to lift your head up higher.

When mounting it in front of an optic, it should be placed far enough in front to ensure that that the on/off knob and elevation/windage adjustments on the Micro are still accessible. It's also important to ensure that the main scope has low profile knobs/turrets that are not too much more than 1/2" tall, or they might obscure the Micro. It's also dependant on the height of the rings used. The compact 2.5-10x24 NSX scope's turrets below were low profile enough not to encroach on the Micro's sight picture.

When zeroing offset optics like this, I've found that it works well for me to cant the rifle so that the optic is directly above the bore (just like I'd be shooting it). I use a swivel bipod while zeroing to place it at the right cant angle. While there are other Micro offset mounts available, the LT-724 is the only one with quick-detach capability.

7/26/08 - Aimpoint's CompM4 Red Dot Sight is the latest CCO (Close Combat Optic) adopted by the U.S. Army, beating out its competitors in the Army's competition for a new CCO to replace the CompM2. The CompM4 is even more rugged than its predecessors, and has a battery life that pretty much eliminates battery life as an issue.

Description: The first impression I got when handling a CompM4 was 'whoa, it's an M2 on steroids'. It felt more substantial and a bit heavier in the hand. While the CompM4 without mount weighs 2 oz more than the CompM2 without mount, looks can be deceiving as the CompM4 with integrated mount weighs the same as the CompM2 with QRP mount (both 11.8 oz). As you can see in the side-by-side photo below of a CompM2 and CompM4, both in LaRue mounts, there really isn't much difference in size or bulk. The heavier weight of the CompM4 sight itself is offset by the integrated mount, eliminating the need for rings (and their weight). The perception of additional bulk is mainly due to the full length battery housing and switch assembly, placed at 1 o'clock on the CompM4's body.

The key improvements over the previous Comps are:

• Integrated mount - The previous Comp models used a 30mm ring; the CompM4 has an integrated mounting interface machined as part of the body. The supplied QRP2 (quick release) mount attaches to the body with two screws and has a torque knob on the left side of the mount. The knob is larger in diameter than the previous QRP mount know, making it easier to turn, but doesn't stick out as much, making it less likely to snag on equipment and gear. A spacer is provided that gives the optimal height for co-witnessing with iron sights.
• Increased battery life - The CompM4 utilizes a single AA battery, which is common worldwide. A single AA battery will provide over 8 years (!) of continuous use at position 12 of 16 and over 3 years at position 13 of 16. At night vision settings, the battery will last 500 000 hours. I'd say that this pretty much eliminates any need for concern about battery life with the CompM4. I turn mine off when I'm not using it, out of habit. But I could leave it on, day and night, for years without needing to change the battery. Of course, I'd recommend periodic checking on the battery to make sure it hasn't leaked or degraded. The battery is housed in the battery tube located at 1 o'clock on the body. The battery compartment cap is knurled and tethered. The CompM4S variant places the battery tube at 5 o'clock on the housing for a lower profile. Note that the CompM4S is not compatible with the lowest 659-HK mount.
• 'Ruggedized' all over - The CompM4 has a completely solid feel to it. The whole thing looks like it's machined out of a solid block of aluminum. Main tube, battery compartment, mounting interface - they're all part of the same piece. The adjustment caps are protected from impact by raised guards in the body.
  The rotary switch knob, once a weak link in the earliest models has been improved and is now sturdier. There is some rotational 'play' built into it. If you're not aware of this, you might think it's broken or loose. At each detent, the knob is free to rotate a few degrees. On the previous Comp models, the knob is attached directly to the rotor, or shaft. On the CompM4, the knob is mechanically 'separated' from the shaft of the switch, and instead is secured and rotates in the sight's body. The force of an external impact or blow to the knob is not transmitted to the switch, but to the body instead, preventing damage to the switch. The detent is also more positive than before.

The adjustment caps are lower profile and easier to remove, and have coin slots just in case. Each cap is tethered with a low profile rubberized strap that does not protrude or present a snag hazard. The front lens opening is threaded for a KillFlash® anti-reflective device, and a removable one-piece bikini cover is provided to protect the front and rear lenses.

Summary of CompM4 Features/Specifications (from Aimpoint):

Reticle/Dot Size: 2 MOA Dot for close combat and long distance engagement
System: Passive Red Dot Collimator Reflex Sight
Magnification: 1x (non-magnifying) parallex free
Eye Relief: Unlimited
Optical Coating: Anti Reflex coating all surfaces. Multi-layer coating for reflection of red light. Band Pass coating for NVD compatibility - Compatible with every generation of Night Vision Devices (NVD).
Battery Type: All types of AA Batteries
Battery Life: Super ACET technology allows up to 80,000 hours (over 8 years) of day-time operation on one AA battery. 500,000 hours of use on NVD setting.
Dot Brightness: 16 positions - 7 night vision compatible and 9 daylight (1 Extra Bright)
Submersible to 150 feet (45 meters)
Improved rotary switch will not suffer damage under normal use.
Mount base is "keyed" into the body of the sight to absorb recoil.
Mount base screws directly into the sight - no separate sight ring is required.
Matches perfectly with Aimpoint 3X magnifier
Improved adjustment caps are easier to remove, and are protected against impact.

Optic Dimensions
Length: 120 mm (4.7")
Weight: 265 g (9.3 oz) sight only - 335 g (11.8 oz) with integrated mount

LaRue Tactical Comp M4 QD mounts - Based on the speed at which they work, I wasn't surprised to see LaRue Tactical come out with their LT659X CompM4 QD mounts as soon as the CompM4 hit the market. And not one CompM4 mount, mind you, but three! The LaRue CompM4 mounts are available in three sizes:

• LT659 (Tall) - This places the center of the optic tube 1.725" above the top of the receiver rail. This is for standard AR15/M4 uppers and aligns the CompM4 with the LT Pivot-Mounted Aimpoint 3X magnifier, LT-Mounted PVS-14 and provides a lower 1/3 co-witness with all standard back-up iron sights.
• LT659-NV (Medium) - The center of the optic is 1.535" above the rail and is the correct height for an 'absolute' (center of the tube instead of lower third) co-witness with BUIS, and compatability with USGI night vision mounts.
• LT-659-HK (Short) - This places the center of the optic tube 1.395" above the rail, and is meant for higher-than-standard receivers like the HK416 and some piston uppers. I mounted it on a Vltor CASV shown below, and it will just co-witness with the iron sights. It'd work better if it were a wee bit lower like LaRue's RAS II Aimpoint mount at 1.225" or the QRP2 without spacer at 1.2", but then, it wasn't really designed for the CASV. I'd also like to see an ultra-low LaRue mount for FALS and other weapons which need the optic as low as it'll go on the picatinny rail. Note that the CompM4S is not compatible with this mount due to the low placement of the battery compartment.

The LT659X mounts are hard anodized with a matte black finish, just like all the other LaRue mounts. There is a single adjustable locking lever with safety lock on the right side of the mount for the typical rock solid and return-to-zero we've come to expect. The mount is not reversible as the CompM4 mounting interface is assymetrical. They have a single recoil lug machined into the bottom of the mount. Again, like the other LaRue mounts, the LT659X mounts are hogged out (hollow) as much as possible to reduce weight without sacrificing strength. While the new Aimpoint QRP2 mount that comes with the CompM4 is an improvement over the 'rail grabber' mount for the Comp, I prefer the LaRue mounts as they're one piece, and the locking lever is lower profile than the thumb knob. Each mount comes with the proper mounting hardware, an allen wrench, a small vial of blue loctite and LaRue's new QD lever adjustment wrench, which is much nicer than the old one.

Shown below is the CompM4 with the three different LaRue mounts to illustrate the difference in heights.

I've illustrated the LT659 on a standard M4 upper and the LT659-HK on a Vltor CAS-V, below. The composite image shows the different in heights between the three mount of the optic on the same upper receiver. At the range, and mounted on my PWS Piston upper with the LT659, there isn't a noticeable difference between the CompM4 and its predecessors (CompM, CompML etc); I got the same familiar sight picture and bright clear dot. Zeroing adjustments on the CompM4 aren't the same as the previous versions, which were 1/2" per click at 100 yards. Instead, the CompM4 has 16mm (about 0.62") at 100m or 1/2" at 80 yards per click. I didn't know this when I sighted it in, so I was wondering why my adjustments weren't as predictable as I thought they would be.

Even though it was very bright out, the Extra Bright dot setting wasn't needed - I think I was using position 14 of 16. Shooting it was uneventful; just the way I like it. One thing to consider is the position of the battery housing. Since the mount is integral to the body, the body cannot be rotated in a ring the same way the previous Comps could be. As a lefty, I had the battery compartment at the 10:30 position so it wouldn't be as much in my field of view. The CompM4S, as mentioned previously, puts the battery compartment near the bottom of the optic, removing it from the field of view and also protecting the switch better. So, pick the model that works best for your preferred setup.

Now, why would one choose the CompM4 over the lighter and smaller T-1 or the less expensive CompM2 or CompM3? In a nutshell, I'd venture ruggedness. I've no way of comparing the actual ruggedness of the T-1 and CompM2/M3 vs. the M4, but based on the way it's engineered, I'd guess that the M4 has the edge when subjected to harsh conditions and abuse. Check some videos on http://www.downrange.tv/show2/ where Freddie Blish from Aimpoint puts both sights through some rough handling to demonstrate their ruggedness.

The T-1 currently will not fit any flip-up scope covers, whereas the CompM4 will accept flip up covers from the previous Comp versions. The larger tube of the M4 is more forgiving than the T-1 when it comes to misalignment of the eye to the tube (if you're using a gas mask for example). The other reason would be availability of replacement batteries. The AA battery for the CompM4 is universally available, cheaper and more common overseas than the coin CR2032 battery of the T-1 or 3V 2L76 lithium of the M2/M3. Even though all three optics have advertised battery lives that number in the years, batteries sometimes go bad or corrode, and need replacing before they actually lose power. For the AA battery for the CompM4, use lithium batteries if possible as they're less prone to leakage, have longer storage life, last longer and weigh less than the alkaline equivalents. While the T-1 is still my favourite red dot sight because it's so darn small and light, I can see why the CompM4 would be the better choice for some situations.

Whichever Comp or T-1 model you choose, LaRue Tactical offers excellent package deals on all the optics with their mounts which are hard to beat, with substantial savings over purchasing an optic and mount separately.

LT659 co-witness

LT659-HK on CAS-V

Composite image of different heights

Front and rear flip-up covers

Old vs. New front covers

Installed on M4

LaRue Compact ACOG Mount LT- 105

3/26/10 - LaRue's LT-105 Compact ACOG Mount is made for Trijicon's compact ACOGs that utilize the carry handle mount with single screw. It's been out for quite a while, but I didn't have the occasion to use one as I didn't have a compact ACOG, until now. In general, Trijicon's compact ACOGs are 3x magnification and below. The 3.5x and 4x ACOGs utilize the same carry handle mount, but a longer version with two screw holes instead of one. Note that some of the 1.5x compacts also come in a "special ring base", which is NOT compatible with the LaRue LT-105 mount. The scope must have the carry handle mount to be compatible with the LaRue base. As with all LaRue mounts, the LT-105 is hard anodized with a matte black finish. It has a single adjustable LaRue locking lever with safety lock. The bottom of the 105 has a single recoil lug - it's as solid as a mount can get. It can be installed on so that the locking lever is on the left or right side of the rifle. The LT-105 comes with everything you need to mount the scope; a screw, locking lever adjustment nut wrench, a hex wrench and a small vial of blue loctite.

LT-105

TA44SR-10 ACOG

Trijicon TA44SR-10 - The TA44SR-10 is one of the latest compact models from Trijicon, and also the smallest and lightest to date. It's almost dwarfed by my TA01NSN ACOG in the photo below, and the TA01NSN isn't a very large scope. It's a 1.5x magnification compact ACOG with BAC (Bindon Aiming Concept) designed for CQB or speed-oriented competition. It weighs only 4.9 ounces. Eye relief is stated as 2.4", but I can actually see the reticle just fine from much more than that (at least 6"). Keeping both eyes open, the TA44SR-10 is meant to be used like a 1x red dot sight. The reticle is a circle dot, with a 23 MOA circle and 2 MOA dot in the center, and a black post below the circle. The reticle is available in red (shown here), amber and green. The reticle is lit by the fiber optic on top of the scope body, and tritium (in the dark). Under bright ambient conditions, the circle dot glows bright red. At night, the circle dot is lit by the tritium. When looking out from a dark environment into a very bright one (like sunlight), the reticle is black. Reticle "washout" can happen under some lighting conditions; when there's not enough ambient light to light up the reticle, and the target is brighter than the dull glow, but not bright enough to provide a lot of contrast so it appears black. The reticle is always there, but can be much harder to see under those conditions than a red dot with which you can control the brightness level. I shot under both sunny and overcast conditions outdoors, and the reticle was plenty bright enough. I have not shot indoors - just looked through it to see how well I could see the reticle. Moving through a house during the day or night, I find the red dot of my T-1 much easier to make out. I had no problems using the 1.5x at very close distances (under 5 yds). I found that while a red dot with no magnification might be less confusing for the eye, the larger circle of the TA44 was also very easy to pick up and place on the target. I have bad eyesight and astigmatism, so I never see my red dots as well defined as reticles. Comparing it to my favourite red dot, the Aimpoint T-1, I don't find the TA44 to be noticeably faster or slower. The circle dot reticle does give me additional hold-over aiming references which I've found useful. From 25 yards to 50 and beyond, I do find that the TA44 helps me be a little more accurate, due to the 1.5x helping me see the target just that much better, and also the more defined reticle (for my eyes). I kept both eyes open for all the shooting with the TA44. The Trijicon glass is like my other ACOG - crystal clear, no visible tint, and targets are crisp and defined. When shooting from different positions where a good cheek weld may not be possible, the long eye relief of the TA44 was very forgiving - I don't think I ever needed to hold it so far away from me where finding the reticle was a problem. It doesn't have unlimited eye relief like a non-magnified RDS, but for most practical purposes, it's pretty close. With today's red dots having incredible battery life, the tritium vs. battery really isn't an issue for me. Ruggedness is probably a wash, too - between the Aimpoint T-1, M4 and the TA44. All of them are good, robust products. One thing that the TA44 might have over red dots is that there's nothing electronic to fail. Even if the tritium dies or the fiber optic illumination somehow craps out, the reticle is still there and functions just like a regular scope. I've had Eotechs and older Aimpoints (Comp M and ML) fail on me, and I'm just a civvie shooter, not in the military or even a competitive shooter, so it's made me aware that electronics can fail. My current T-1s and M4 have been going strong, though, with the much improved switches over the older Aimpoints. Where the red dots like the T-1 have the edge (in my opinion), is the ability to control the brightness of the dot. I do not discount the importance of having this ability, because even with some red dot sights that adjust automatically (like the Docter or Fastfire), there are conditions under which the dot is too faint to see, just like the reticle on the TA44 (and other fiber optic lit reticles). I'd love to see a TA44 with an electronically lit reticle and brightness control.

TA44SR-10

Size relative to TA01-NSN

TA44SR-10 reticle

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Anyone who's serious about getting the best available QD mount for their optic should look no further than LaRue Tactical. Besides mounts, LaRue also offers sights, handguards, targets and a host of other accessories - all made with the same quality and dedication, so check the other products out and give them a holler. LaRue is also constantly working on and introducing new products, so even when the 'stars at night, are big and bright, deep in the heart of Texas', you can be sure than the machines are cutting and the chips are fallin' at LaRue.

7/11/09 - What's a Cat Tail for a scope? That's the first thing I asked when I heard of them, but when I saw some pictures, it was immediately clear. A Cat Tail is a power throw lever for a variable power scope. It's an attachment that enables the power ring to be rotated more quickly and easily by providing added leverage. This can be advantageous if the user needs to change the power setting on their scope rapidly, or has a scope with a stiff power adjustment ring.

The Cat Tail here is made by Charlie Drissel, who is a Colorado shooter and CNC Machinist/Tool maker. Charlie is a graduate of the Colorado School of Trades' Gunsmithing program and also has his degree in Tool and Die Technology.

Description - The Cat Tail is a split ring that secures around the power ring of a variable power scope. Shown here is the one to fit my Leupold Vari-X III with 1" tube. The Cat Tails are machined from 6061 T6 aluminum and finished with a Type II Class 2 black anodize per MIL-A-8825. The two small socket head cap screws are black-oxide 18-8 stainless steel. Most weigh an average of 0.5 oz. All edges are rounded.

The Cat Tails are custom designed to fit specific models of scopes, as each one has a different power ring. At the time of this writing (updated 8-28-09), the current Cat Tail models in production are:

• Burris XTR (1-4x24), TAC30, MTAC
• IOR Valdada Pitbull 1&4
• Leupold Mark 4 CQ/T, Mark AR, Mark 4 scopes WITH illuminated reticles, and WITHOUT illuminated reticles
• Leupold VX II (1-4x20mm), VX-R
• Leupold Vari-X III (1" and 30mm tubes, 3-9x50 30mm European)
• Meopta R1 (1-4x22 RD), also fits Horus Talon 1x4-24
• Millett (1-4x24 DMS)
• NightForce NXS Compact
• NightForce NXS & NXS F1
• S&B (PMII 3-12x50, small bumps)
• S&B (ShortDot, 5-25x56 PMII and 4-16 PM II)
• Trijicon Accupoint TRs
• Weaver Classic V-3 (1-3x20mm)

Notes - Installation was bone-head simple. The Cat Tail fit perfectly onto the power ring on my scope, and after putting a bit of blue loctite on the screws, I was done in less than a minute. The addition of the Cat Tail makes overcoming the resistance of rotating the power ring much easier to adjust. I don't have to pinch the adjustment ring with my index finger and thumb anymore, turning a bit at a time - now it's much easier just to push or pull on the lever, and it's also much easier in the prone position. Some scope power rings are easier to turn than others, while some can be quite stiff. This can be worsened when they're wet or slippery.

Another advantage to having a Cat Tail on a scope is that it provides a quick visual or tactile indication/confirmation of what power setting the scope is on, depending on the position of the lever (once you're familiar with it, of course). You can glance down and see the lever more easily than small numbers on the ring, lining up with the index mark. You can also feel where it is (generally to the far left or far right) without looking. For me, I think the Cat Tail is a great addition to my scope and I look forward to adding it to others when the models are finally available.

Charlie doesn't have a website yet, but has a section on the Brian Enos forum with more information on models, pictures and purchasing info, so click on the link. The Cat Tails are also being sold through shooter's connection, LaRue Tactical and Cactus Tactical. Charlie also sells them direct - email him at drisselc@msn.com.

8/28/09 - Charlie just came out with some new Cat Tail models (see updated list above), and one of them is the model for NightForce NXS Compact scopes. Notice that the NXS lever is styled differently from the one for the Leupold. Instead of the skeletonized 'A', it's narrower with three lightening holes.

The 2.5-10x24 NSX scope shown here is a great optic - clear, bright glass with illuminated reticle, but power ring can also be a bit stiff. I also don't find the scalloped 'teeth' on the power ring particularly grippy. The Cat Tail installs over the scalloped ring, and once snugged down (it should not be over tightened), provides a solid lever which makes rotation of the power ring so much easier. As with the Leupold Cat Tail, a quick glance at the position of the lever can tell you what magnification setting the scope is on.

1/4/08 - Troy Industries Folding Battle Sights have been out for a while now and have become a very popular choice (and the standard for which others are compared to) for AR-15 back-up iron sights with civilian and military shooters and military alike. They've proven themselves to be rugged and durable enough to withstand the rigors of battle. It's no wonder that Noveske Rifleworks chose Troy sights as the standard on their complete rifles, and also offer them for sale with the distinctive Noveske Iron Cross logo.

Troy makes two styles of front sight - their original 'globe shape' with a HK-style circular aperture, and the newer M4 style front aperture with the 'wings', which offers the same sight picture as the standard AR15/M4 front sight. John Noveske chose to carry the M4 style, as he grew up with an M1 Garand, and has an instinctual comfort with the M1/M4 style front sight profile. He pointed out that many shooters, military trained or not, have the same relationship with that style. With the HK style, the eye naturally centers the target into the center of the circle, even if the actual zero of the weapon puts the post higher or lower. Therefore, he sees the HK style front sight only effective on sight systems which have a non-adjustable front sight post. John was very happy to see the M1/M4 style change on the Troy front sight. The M4 style is easier to adjust than the hooded style.

The front and rear battle sights fit on any 1913 rail, and place the sights are the height of the standard M16/M4 sights. The sights are made of blackened stainless steel and MIL-SPEC Type III Hard Coated T6 Aircraft Aluminum. They're available in USSOCOM Flat Dark Earth and Black with the Noveske Iron Cross logo laser-engraved on the front of the sight base.

Front Battle sight - The front sight has adjustable elevation with a square post. An adjustment tool is provided with each sight. The sight is .500" when folded for a low profile. When deployed, the front sight is at the same height as the standard front sight. Deployment of the sight is accomplished simply by flipping it up. It locks in the up position with a stainless steel system. The grooves on the side of the sight aid in gripping it. The release button on the left side of the sight is depressed to fold it back down.

Rear Battle Sight - The rear sight deploys and stows just like the front, and has the same type of release button on the left side. The dual same plane aperture is protected on both sides by blades. When the sight is first deployed, the large aperture is the default. The adjustment wheel is also protected and can be turned using a coin or flat screwdriver. It has positive click detents and provides 1/2 MOA of windage adjustment with each click for the standard M4 sight radius. The actual value will differ if the sight radius is longer or shorter. Since the sight is the standard height, the rear battle sight can be replace the M4 carry handle and be used with the standard front sight base. When folded, it's a low .460 profile and will fit under most optics.

The Troy/Noveske Battle sights are solid and provide a familiar, clear sight picture while remaining simple to use and adjust. The Noveske logo just adds a very cool aesthetic touch.

10/6/06 - Midwest Industries, Inc. offers front and rear flip-up backup irons sights. Both sights are made from 6061 aluminum and mil-spec hard coat anodized for durability. They clamp to the rails and receiver with an allen head screw.

The front flip up comes in two version - the rail mounted version (MCTAR-FFR) and the gas block mounted version (MCTAR-FFG). Shown here is the rail mounted front flip up - the FFR. The FFR has the AK-style open-top ears. A standard A2 front sight post is used. When closed, the sight is about .625" above the rail, and below the field of view of magnified optics. To deploy the sight, you just flip it up, and it locks in place. The close it, you press a small detent button on the left side while folding the sight down.

The rear flip up sight (MCT ERS) has an A2 style standard aperture with A2 windage knob on the right side. Thick ears protect the aperture from knocks and bumps. Flipping the sight up locks out a detent button on the left side which must be depressed to fold the sight down. The windage knob adjusts the POI .65 MOA per click for M4 sight radius and .49 MOA on standard A2/A4 lengths. When folded, the highest point of the sight is about .8" above the rail. Because of this, it won't normally fit under scope eyepieces - a lower profile rear sight is needed for that. But it works well behind dot optics like the Aimpoint or Eotech (shown here). Like the other MI products I've used, these back-up iron sights are sturdy and well made.

3/25/07 - Not a review, as these sights are not widely available (if at all), but shown here just for reference, and the fact that I could find no good photos of these sights anywhere on the internet. Even though these sights were designed for the HK MP7 A1 PDW, I found that they function just fine for the M4 as back-up sights. They're similar in design and function to the Knights 300M rear BUIS and their front rail-mounted flip-up. A spring loaded plunger holds them in the up or down position - there's no lock. The MP7 sights include pistol-type sights when folded down - there's a front sight blade and rear, which can be used on the MP7 when no optics are mounted. On the M4, the pistol sights are too low to be used, but they'll work on weapons with a higher top rail. The sights clamp to the rail and are tightened by a philips head screw.
The front has a round post which can be adjusted for elevation without tools (there's a detent every 1/4 revolution), and the rear has a peep aperture. The rear aperture is approx .12" - larger than the small aperture on a standard AR sight but smaller than the larger aperture, and is a good compromise between the two sizes, in my opinion, for a back-up sight. Sight picture is almost identical to that of the M4/AR. Windage adjustments are done with a coin or anything that fits in the slot on the protected windage dial. I measured the sight height above the rail to be the same as M4 sights - about 1.4". They're a relatively streamlined, compact design, and well made. Not necessarily more robust or 'better' than the other backup sights out there, just a bit different.
More photos mounted on the rifle are here, in the LaRue Irondot writeup.

The only drawback to these sights is that they're difficult to get - I've never seen them offered for sale anywhere. I can't help anyone with information on how get a set, so please don't email me asking where to get them, sorry.

5/11/07 - When it comes to mounting MRDs (Mini Red Dots) on magnified optics; scopes namely, the choices are pretty limited. ARMS offers rails that place the MRD on top of the scope - this may not work well with tall turrets and make it difficult to adjust the MRD. LaRue (reviewed above) make a special MRD ring for their scopes, which offsets the MRD just to the side of the scope at the 10:30 or 1:30 positions. But you must have LaRue rings and mounts. Victor from Tactical Night Vision Company (TNVC) is now offering his SAR mounts as alternatives to current mounting options that will work with any 1" or 30mm scope tube. The SAR1 (not pictured, for 1" tubes) and SAR3 (for 30mm tubes) add a rail to any scope tube that can be used for mounting an MRD. They're machined aluminum with a hard anodized finish.

The SAR3 is essentially a 30mm scope ring with the addition of a length of rail machined as part of the top ring. The rail is 1.77" long, and the top of the rail is about 0.47" from the scope tube. It weighs 1 oz. The cross cuts are spaced closer than M1913 spec - to provide more positions for typical cross bolts on MRD mounts. The upper and lower halves have four screws that clamp it around the scope tube - a simple, two minute installation. Note that a Weaver/Picatinny mount must be used when mounting an MRD, usually supplied with the MRD. The SAR3 enables the user to mount an MRD on pretty much any scope. It can also be used for lasers or IR designators on bolt guns.

The SAR2 mount is actually an adapter - 5mm-11mm dovetail to Picatinny for .22's or similar weapons that have dovetails on them. The SAR2 enables you to mount a weaver/Pic optic on the dovetail. It's 1.75" long and 0.5" high. On the bottom of the SAR2, one side ofthe dovetail clamp is fixed while the other moves when the cross bolt is adjusted. Because of this, and depending on the width of the dovetail, there might be a small lateral offset of the optic off the centerline of the weapon - the smaller the dovetail, the larger the offset. For MRDs, and what they're used for, it's negligible.

Shown below is a Docter Optic MRD mounted using the SAR3 and SAR2 mounts. First, I installed the SAR3 on a NightForce scope, and I rotated it so that the MRD was at the 10:30 position, for left hand use. A slight cant to the right of the rifle is all that's needed to acquire the dot. I highly recommend using a laser boresighter to get the dot in close.
I put the SAR2 on an old AMT Lightning (stainless steel copy of the Ruger 10/22) which had an integral .22 dovetail on top of the receiver. As you can see in the photo, the MRD is offset slightly to the right, off the centerline. I'd have prefered it if the clamps both moved and the mount was self-centering (if using a magnified optic), but that would add complexity to the design and manufacture of the part. For its intended purpose, the SAR2 works just fine.

The mounts have not been added to the TNVC website yet, so contact Victor directly if you're interested- victor@tacticalnightvision.com. More pics and info here.