HOLOSUN HS515C Paralow Circle Dot Sight


Now if you wanted to know why I should be considered as a reliable source of information, perhaps that due to the fact that I have over 30 years of army experience behind me, including two Gulf wars, and a couple of decades of active reserve service.

Now, with all that said and done, I intended to put this sight, as I have done for other sights, through some extreme testing conditions including excessive bumping, dropping and drowning. I wanted to see how this model handled dust, abrasion, impact shocks, and underwater performance.


Before I get into the test results, let’s take a look at the Holosun HSC Features:


Power Source

Holosun is the designer of their unique shake and wake system, which has not been copied yet, but I expect one day soon to see this in other optics. The shake awake is essentially a motion detection system that enhances the two power sources already in place. Solar power for daytime reticle illumination and night vision CR2032 cell.

The shake awake primarily comes into action at night when you want to save on battery power, and it deactivates the power after 10 minutes of no movement. Once a movement is detected, the system will open up the power, and your reticle will regain its illumination. Bottom line; this unique combination of power and control gives you an amazing 20,000 hours of battery life. The actual voltage is 3V AC to power the illumination.


The solar power source is from a silicon solar cell set on the top of the sight. You want to keep that cell clean to maximize efficiency.

Illumination Control

The illumination levels come in 12 daytime settings and two for night vision, so you get enough variance to cover any ambient light conditions. The system adjusts the illumination automatically based on the ambience, however you get to change the illumination control manually as well, so you can do this by pressing on the plus and minus buttons on the side.


The manual illumination mode is reached by pressing the “+” button for 3 seconds, and the auto mode is again reached by pressing the same “+” button for another 3 seconds.


This model comes with two options, the 65MOA circle with 2 MOA dot or the 2MOA dot alone, and the color of this one is Red. The W&E Range is ±50MOA, and you get a 0.5MOA adjustment per click.

The standard reticle is a central 2MOA dot, centred in a 65MOA circle and comes with four positioning points. The diameter of the circle reticle represents approximately 5′ 5″ at 100 yards (170cm at 100m). To change the view, (remove the circle) press the “-” button for 3 seconds, which can only be done when the sight is in manual mode.



This is a parallax-free lens (Parallax is ≤± 1MOA) whose size is 20mm and provides a standard 1x magnification; the lens comes with a flip-up cover to protect it when not in use. It also integrates a kill flash coating.


This model comes with both quick-detachable high and low mount, and the high mount is used on standard AR platforms for a lower third co-witness. The mount bracket is adaptable for Picatinny Rails only.



The buttons are set on the side of the body, inset to make adjustments safer and easier as well as to protect the adjustment knobs from any abrasive damage. The lens covers come with a molded knob tool, so you don’t need a screwdriver.


The body of this sight is made from a 7075 T6 aluminum alloy, machined and finished with an anodized finish. The anodized finish is not really making your aluminum block hard like steel, it’s just making it secure from natural oxidization, so you don’t get a white oxide powdery coating, but a black matt anodized coating.


The body dimensions are 2.44” x 1.77” x 1.37”, and it weighs 7 ounces and it comes with a vibration resistance of 1000g. Its central height is set at 1.63”.

HOLOSUN HS515CU Circle Dot Sight


Operating Range

Just like all equipment, the Holosun 510C can only operate in a finite temperature range, and it is impressive when considering where you would want to go with it. The standard operating temperature is ranged between -10°C to 50°C, while the storage temperature is set between -40°C to 70°C.


This model comes with an IP67 rating, which means you can submerge it in water.


The Results

First off, it’s astigmatic friendly, so for anyone suffering from astigmatism; you are in luck. Apart from this little fact, the 2 MOA dot with its 65 MOA circle looks crisp for everyone, even Mr Magoo.

So first off I took it for a rough and ready round in the swamps, and yes, waded around in murky waters too. This lil sight handled the dirty water admirably since it has flip covers, you don’t get any gunk clogging up the view.

The next test was in the desert, and yup, dust is not an issue, neither is dropping it down three stories. Jumping around, aiming, shooting and then by accident on purpose banging into walls and columns that beastie still performed well.


Now we come to illumination performance, and yes, minions were involved in this one. Lugging it around in the sweltering sun does wonders for its clarity, and even as the day waned and the sunset. Going into the greying hours of long shadows the reticle was still actively appropriate.

Sure, I changed over to the power cell, and then came the dead of night (woo). Silence encroaches, quietly stalking a pray.

Looking out for those glowing eyes reflecting back in the dark, I lay down and put my AR aside, looking through occasionally, the sight switched off alone and then it woke up when it sensed movement, which just happened to be me touching the side of the AR slightly and snap the reticle was visible again.

Now back to the auto adjustment, it works fine in most cases, but I found that when you are in differing light areas, where there is a shadow, or when aiming outside inside, you need to consider manual adjustment control to get a more accurate result.

Remember, this is for those slow shots when you are moving and shooting, you don’t have time to play with illumination, and its best to keep the auto-adjust on and leave the fiddling for quieter periods.


In terms of reticle accuracy, well that’s just up to me as the shooter, but the reticle retains its integrity and clarity even out to 150 yards.

At any range you will zero in effortlessly, and you use the elevation adjustment set on the top of the sight while the windage adjustment is set on the right side of the body and you use a screwdriver that has been molded into the lens caps to make the adjustments, hence; no tools required.

To move the red dot up, rotate the elevation knob right and to lower it; rotate the knob left. For windage adjustments, rotate the knob to the right to move the dot right, and obviously left to move it left.

Simple. The plus and minus buttons are easy to press for illumination control, so overall; operationally this sight is highly intuitive and user-friendly.


OK, so down to the basics; this sight is as simple to operate as you can get, but as complex and advanced as you would hope to have within the price range.

It comes with unbeatable power source and control, the crisp quality of the reticle, the illumination levels and the shake awake all add to provide a perfect target acquisition solution.

One word of caution; if you try to turn a knob and it won’t budge, it means it has reached the end of its thread. Do not try to force it or you will damage your sigh mechanism.

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