Home Reviews Eotech 552 EOTech 552 Holographic Weapon Sight

EOTech 552 Holographic Weapon Sight

by Arnie

EOTech 552 Holographic Weapon Sight
By Scott

Features Optics – Transmission holography
(100% parallax free)
Magnification – 1x unlimited eye relief
4” x 1.8” x 2.25” (Model 551),
5” x 1.8” x 2.25” (Model 552)
Weight – 11.5 oz. (326 grams)
Temperature – -20 to 150F (operation)

-40 to 160F (storage)
Sealing – Waterproof & Submersible
(to 33 ft depth) / Fogproof
Color/Finish – Non-reflective black with hard finish
Adjustment (per click) – 0.5” at 100 yards
Adjustment Range – +/- MOA travel
Mount – 1” Weaver dovetail / Picatinny rail
(Mil spec 1913)
Return to Zero – Repeatable to 1 MOA after remounting
Battery Life – 100 hours for ‘N’ Model
500 hours for ‘AA’ Model
Reticle Options – 65 MOA ring w/ quadrant ticks
w/ 1 MOA aiming dot

The EOTech HWS reflex sights began to be used among the special forces around two years ago (2002) and some of the first pictures of them in use were taken during operations in Afghanistan (Operation Enduring Freedom). Since then they have rapidly gained widespread acceptance among the military and law enforcement communities. Several thousand units have been purchased by SOCOM and, more recently, they have been issued to the US Army’s Stryker brigades currently deployed in Iraq.

The HWS is a reflex type sight. It has no magnification and produces an aiming mark which is visible while both eyes are open and focused onto the target. It is illuminated from a battery source and is designed primarily for engaging at short-medium ranges (0-300 yards).

The EOTech HWS is similar to the red-dot (Aimpoint) type sights that most airsofters will be familiar with but has a number of significant differences:

  • It produces no light signature. Other types of illuminated sights betray your position – on sights with clear lenses (e.g. Aimpoint type) the projector LED is visible from the front at night and on sights with reflective lenses (e.g. Trijicon Reflex) produce a coloured flash when sunlight catches the lens. The HWS is illuminated by a laser which fires upwards and is not visible from the front. Also, some models are night vision compatible which eliminates the requirement for infra-red laser devices which betray your position to other NV users.
  • The reticle is produced by holographic projection. This means that the reticle is parallax free so the aiming point is accurate even when it is not centered in the window. Also, every part of the screen contains all of the information required to form the reticle so no matter how damaged or obscured the screen becomes the sight can still be used as long as there is a part of the screen still intact.
  • The HWS is designed specifcally to work with the M16/AR15 series. It will work with other weapons but it works especially well on an M16. With the sight mounted on the weapons foregrip (either onto a RAS/RIS or using a drop mount from the carry handle) or mounted on the receiver with a chopped carry handle rear sight, the reticle can be used through the iron sights. With a proper sight picture formed, the ring of the reticle sits inside the ring of the rear sight with the central dot sitting on the center of the front sight post. With both eyes open and focused onto the target you barely see the sights – just the reticle lying on the target.
  • Resistance to damage. The projection mechanism is inherently very strong and uses the rear screen to create the reticle – not the front screen. The front screen is particularly strong and is constructed of 3/16 laminate which is much stronger than the front lenses of most scopes. The hood which wraps over the optics to protect them from knocks is 2.5mm thick steel and is up to taking a lot of abuse. The HWS is also waterproof to 33 feet (10 feet on some models) and can be submersed indefinately.

The HWS comes packaged with a manual, batteries, an allen key (for mounting the sight) and an a thumbwheel bolt which can be used to replace the allen bolt and eliminate the need for the allen key.

The base of the sight has a dovetail mount suitable for weaver/picatinny rails. This has enough adjustment to fit the slightly oversized and undersized rails often found on airsoft parts. The allen key used is a pretty odd size – 7/64 of an inch. I would guess that this is deliberate – many armed forces don’t allow their soldiers to change the layout of their weapons and using an unusual allen bolt would provent the soldier from removing the sight.

Battery installation is very well thought out. A lever on the top of the battery compartment can be lifted to allow the whole front of the sight to be removed. This is essentially a cartridge which holds two batteries. Closing the lever cams the compartment rearwards against a gasket. The amount of force applied is quite considerable and good watertight seal is formed. This can be done while the sight is mounted.


Elevation and windage is adjusted by controls on the right of the sight. These are slotted for use with a screwdiver or coin – they cannot be adjusted without a tool of some kind. The adjustment has discreet clicks and the range of adjustment is fairly large. The sight comes pre-set with the reticle centered and this was spot-on for my M16.

On the rear of the sight are the controls. These consist of three buttons – Up, Down and NV (on certain models). Tapping up or down turns the sight on and sets it for auto shutdown in eight hours or four hours respectively. Pressing the up and down controls changes the brightness by one level. There are twenty levels and the sight defaults to level twelve. Pressing up and down together turns the sight off. The NV button switches to night vision mode which is simply a very dim reticle which will not overwhelm a night sight. There are ten brightness levels in NV model. These buttons can be easily reached with the thumb of the supporting hand if the sight is mounted on the foregrip. Turning the sight off is quite tricky but the battery life is excellent (1100/600 hours for AA lithium/alkaline models and 200 hours for N models) and the sight will always turn of a maximum of eight hours after you last pressed a button so there isn’t really a need to turn it off.

There are a number of models available:

  • The 502 is the oldest model. It uses N cells and lacks the protective hood.
  • The 510 range is waterproof to 10 feet and is available for N cells (511) and AA (512) It is also available with special reticles for use with less lethal projectors.
  • The 550 range is waterproof to 33 feet and has night vision compatiblilty. It is available for N cells (551) and AA (512)

The AA models are more desirable as they have a longer battery life, use a more common battery and (I think) look better. However, the N models can often be found slightly cheaper because of this. I got a good deal on a 552 on eBay so that was the model I ended up with.

The sight was a little heavier than I had been expecting. 326 grammes doesn’t sound like much but on a small unit like this (130mm long) it’s suprisingly heavy. A lot of this is due to the hood which is a big chunk of the weight. I wouldn’t mind seeing this replaced with aluminium or carbon fibre. However, it’s not a heavy sight compared to many.

Mounting was a piece of cake and, as mentioned above, it fits fine onto the not-quite-picatinny rails found on airsoft kit. The sight comes pre-zeroed and needed no adjustment on M16. The manual covers mounting and zeroing as well as operation and although very concise is completely clear and covers all aspects of use.

In use the sight is extremely quick – there is a very wide angle through which the reticle can be viewed and this allows you to get onto aim very fast indeed. The reticle is pretty bright on the default setting and is hugely bright on the max setting – the top couple of settings would only realy be useful in desert conditions or against brightly lit snow. The dimmest settings are low enough to to intefere with your (natural) night vision. I would have liked to see an automatic brightness compensator – this is a feature found on some russion sights and I would compliment the HWS very well.

The central dot is very sharp but the ring is slightly fuzzy although this reduces the further away you focus. The ring is 65 moa so it is 65 inches wide at 100 yards and 32.5 inches wide at 50 yards. I take 50 yards as the range where accurate shots become possible. At this distance the ring is wider than a persons’s shoulders. I would have preferred a 50 moa reticle (25 inches at 50 yards) as this is just right for a person’s shoulders and is ideal for airsoft. However, this is not a major issue but I will have to adjust to this for range bracketing.

View through the HWS without any iron-sights

View through the HWS with iron-sights
(this shows a head raised position looking just over the top of the iron sights)

Overall, this is a top-quality sight with a price tag to match. While it does have some advantageous features (especially the lack of optical signature) and it is a piece of kit that you can rely on absolutely, the price is steep. The old 502 models can be had for around UKP 170 on eBay and the 550 range are around the UKP 250 mark.




on this review in the forums

Thursday, August 5, 2004 11:10 AM
Copyright 2003 ArniesAirsoft

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