Optic Review: Holosun AEMS Reflex Sight (Red)

So a bit of disclosure before we get into the review, this optic was lent to me at no cost by Tactical Kit. The agreement we’ve always had is that I’ll only review an item if I like it. I won’t pull any punches and if I feel that an item is coming up short in a particular area, It’ll be mentioned within the review. – Dan”


So, another reflex sight review, huh? And what exactly makes this one so special?

Two words: Form Factor


For about a decade there’s been a trend to simply clone Aimpoint’s T1 micro red dot design, sell it for less money and add a few more features: Vortex, Holosun, Sig… They’re all playing the same game, rarely moving far from the 20mm tube form factor.

The trade-off for sticking to a particular design, no matter the benefits, is that you come up against the same limitations time and time again. In the case of the Aimpoint T1, it’s the narrow field of view offered by a 20mm tube.

There was only really one way for Holosun to escape from the Aimpoint T1 clone cycle, and that was to completely change the shape of the sight.

It’s not the first time they’ve tried… Their 510 and 512 series are rather different to anything else currently on the market and instantly recognisable, but what about something a little smaller and lighter? Well, that’s where the AEMS comes in.

Holosun’s more traditional “Aimpoint” influenced design, the HS503CU.

When you first look at the AEMS, it’s that aggressively square, obelisk-like profile that initially marks it out from the competition. However, don’t be fooled into thinking it’s purely an aesthetic choice, the AEMS is all about function before form.

Measuring 64mm in height, 37mm in width and 57mm in length, the AEMS is slightly shorter, not quite as long and only a touch wider than the more conventionally “T1” shaped HS503CU. It is a touch heavier at 111g, but it’ll sit at a point on the rifle where weight isn’t as much of an issue as say; a light, foregrip or suppressor.

AEMS (Top) HS503CU (Bottom) – measurements are in inches.

The AEMS is constructed from 7075 T6 Aluminium, which is machined into shape and then anodized in black. It’s tough, it’s well finished and it looks and feels incredible.

It also comes complete with it’s own skeletal mount, providing standard a lower 1/3 co-witness allignment with AR-15 type iron sights. Although you should be aware that this mount is proprietary, currently it’s also the only mount available for the AEMS.

The angular shape of the AEMS allows for more glass within a comparable sized sight unit. To put it in quantifiable figures, a 20mm red dot sight has a total sight picture area of 3.14cm2, the AEMS has an area of 6.19cm2.

That’s twice the area of glass, all in a package that’s as near as damn it, the same size. If that doesn’t impress you, go ahead and put some tape over 50% of your current optic and see how much difference it makes to your sight picture.

When you consider that this has nearly twice the area of glass as the T1 design but isn’t any bigger, you’re starting to see why it might be an optic that’s worth looking at.

Let not get the wrong end of the stick, I’m not saying “Don’t buy an Aimpoint T1”, far from it. But comparing the AEMS to the more traditional design of the T1 shows how revolutionary the AEMS’s form factor really is.


But what does AEMS mean? It stands for Advanced Enclosed Micro Sight, rather simple really and doesn’t give much away, other than it features an enclosed emitter (as do most other “long gun” optics).

The primary reason for having an enclosed emitter, is to protect the system from the elements. Some red dot designs such as the C-More reflex offer a fantastic field of view, but don’t really have the durability to withstand the environment. Other designs such as Aimpoint’s catalogue of rifle and carbine optics offer a far more durable option, but at the expense of a bulky housing, increased weight and a smaller sight picture.

Open emitter reflex sights are becoming far less attractive to those who carry their firearm in all weathers, even those used on pistols are slowly being nudged aside by small closed emitter optics such as the ACRO.

They’re harder to keep clean (The RMR in particular is a sod to clean, especially the inner section of glass), they’re also prone to becoming waterlogged or otherwise cluttered with debris.

The AEMS doesn’t have any of those concerns, it’s emitter is fully enclosed with a nitrogen purged, airtight seal protecting it from the elements. Additionally, a pair of flip down covers are built into the sight and provide protection to both the ocular and objective lens’.

These covers are clear, giving you the option of keeping them closed whilst using the optic, protecting the multi-coated, reflective glass from the environment. But be aware, additional layers of glass can sometimes add a few unwanted reflections, so for the best clarity you should shoot with the covers off whenever possible.

The covers are also removable via a pair of small star-drive bolts, making replacement or reinforced “Airsoft” covers a real possibility. I’m not brave enough to shoot an airsoft gun at the cover, but I reckon at range it’d be enough to prevent damage or contacts to the primary lenses.

The battery used is a single CR2032, this will give up to 20’000 hours using the full reticle or 50’000 hours with just the dot selected. The removable tray is mounted onto the side of the AEMS, this allows you to change out the battery without removing the optic and subsequently disturbing it’s zero.

The primary controls for the sight are very simple, a pair of rubberised buttons, one marked ➕ and another ➖. These are used to turn the sight on and off, adjust the brightness of the reticle, choose the reticle displayed and also control a few other inbuilt features.

The adjustment for windage and elevation are both unshielded dials with a simple slot, the left hand side being home to the windage dial and unconventionally, the elevation adjustment is mounted on the right hand side (as opposed to the top of the sight).

Each graduation click moves the point of aim half an MOA (0.5 inch at 100 yards), and there’s a total of 25MOA within both dials. This should be more than enough for anyone using this sight, and the ability to dial in at sub-MOA accuracy is of great benefit to those shooting at longer ranges.

A tool is provided to adjust both dials, it also has a star drive built into the other end to both attach the sight to your rail and also remove the aforementioned battery tray.

Functions and Controls

To turn the sight on you simply press either the ➕ or ➖ button, to turn it back off you press both at the same time. Pressing either button whilst the sight is on will adjust the brightness of the reticle, with 12 total brightness settings available.

The lowest two are suitable for use with night vision devices, the rest range from dim to very bright. Rest assured, I didn’t feel like there was a scenario I couldn’t find a suitable brightness setting for.

Under NODs, the reticle is easy to locate and provides a good visual reference for your point of aim.

The other functions that are included will be familiar to anyone who’s already used one of Holosun’s other reflex sights:

Multi Reticle System

Holosun’s multi reticle system uses a 2MOA dot with a 65MOA ring. The ring has small marks at the top, bottom and sides, assisting you in keeping the rifle level, and with practice they can also be used as holds and range indicators. The model I chose to look at was their red model, but a green version also exists for those who want it.

A rather wide field of view, perfect for engaging multiple targets.

You can select between dot and ring, dot on its own or ring only. Most will use the full reticle, it’s well laid out and not cluttered, it allows for rapid dot acquisition and works great under night vision. But some people will prefer the traditional dot, it’s simple, it doesn’t have any distractions and it’s ultimately the primary aiming point of any well zeroed rifle.

But what about the ring on it’s own? Well it just so happens that a 65MOA ring is roughly equal to the dispersal pattern of 00 Buckshot at 25yards. Maybe not accurate enough to gauge whether or not you’ll hit that hostage, but accurate enough to ensure you put most of your lead into whatever you’re aiming at.

Shake Awake

The AEMS features Holosun’s Shake Awake technology, meaning that after a preset amount of inactivity, the sight will automatically turn itself off. This can also be set at 10 minutes (default), 1 hour, 12 hours or you can turn this feature off, although it’s a great battery saver, so why would you? Please note, shake awake won’t work if you manually turn off the AEMS.

Solar Failsafe

A Solar Failsafe function offers shooters the ability to harness the power of the sun, saving battery life and maybe keeping your optic in the fight. A small ruggedised photovoltaic cell on the top of the optic allows the sight to be powered by any ambient lighting, even most artificial lights will provide enough power to keep the reticle lit well enough for shooting.

The photovoltaic cell is well protected by the sight housing, I’ve yet to see a damaged Holosun cell.

This Solar Failsafe option will also automatically sense the ambient light and adjust the brightness of your reticle to suit the environment, once you hit your preset battery power level, it’ll stay on that brightness.


In Use

My recent transition to firearm shooting has provided me with the opportunity to put accessories through more of a test than Airsoft alone provides. Whilst I love Airsoft, this optic is designed to be used on a firearm with a much higher degree of accuracy than any airsoft replica can offer, and now that I have the ability to run optics as intended, it’s something I’ll be doing on all future reviews.

The Tippmann M4-22 test bed, seen here with a Sightmark Ultrashot Reflex Sight.

Mounting the AEMS atop a Tippmann Arms M4-22, I quickly discovered one of the key drawbacks of a cheaply made, cast upper receiver… The top rail on the Tippmann’s receiver is annoyingly just off-spec.

This meant that the AEMS’ in built anti-recoil lug refused to sit within the rail. However, I was able to stick it onto the machined free-float rail on the front of the AR and resume testing. Not something you can blame the Holosun for at all, but worth noting that work will be needed to make it fit a poorly made rail, no matter whether it’s an airsoft or firearm.

After zeroing the AEMS, I ran the rifle through a selection of pop up and multiple quick reaction targets. This really was playing to the sight’s strong suit, with it’s increased field of view and “dot and donut” reticle, the AEMS proved to be more than up to the job of putting accurate shots down range and on target.

After using the AEMS on the range, I reverted back to Airsoft and trialled it in conditions I’d be likely to be using it in at a CQB or night game. Mounting it onto my short barrelled GBBR replica and donning my NODs, the sight comes into it’s own.

The AEMS mounted onto my MWS based URG-I Shorty build.

The wider field of view presents an almost unobstructed sight picture and allows for very quick target acquisition, meaning that you should (in theory) be able to shoot multiple targets quicker than when using a 20mm tube based reflex sight.

So are there any negatives? Well, until other mounts become available, we’re stuck with what you get in the box. That’s not entirely bad, it’s a good lightweight mount and doesn’t add unnecessary weight to the package. But different height mounts are something that will allow this sight to find it’s rightful place on shotguns, sub-guns and other firearms that benefit from either lower or higher profile sight placement.

It’s not the cheapest sight that Holosun offer, and retails at around twice the price of a HS503CU. But it’s not designed to compete with their own cheaper sights, it’s priced to compete with the Trijicon MRO and dare I say it, the Aimpoint PRO.

Overall, the AEMS is a really exciting new addition to the Holosun range. A fully featured and capable rifle optic in a micro reflex sight sized package. It’s something different to the norm and tackles a very real issue. For that reason alone, I think Holosun deserve a second look, even from those who might initially disregard the “budget” label attached to the manufacturer.

Thanks again to Tactical Kit for providing this optic for review! The Holosun AEMS is available in the U.K. through Tactical Kit, with stock available for immediate dispatch worldwide.

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