Holosun 510C Review

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Holosun 510C

Are you looking for a quality red dot offered at a competitive price? If so, one worthy option to consider is the Holosun 510C.

The Holsun 510C is specifically an open reflex red dot with an aluminum construction. It’s designed for use with rifles or carbines, and offers a few high-tech features that are traditionally only found on more expensive red dots.

This guide covers the reasons to consider investing in a red dot, the top qualities to look for in one, the primary features that the Holosun HS510C has to offer, and its pros and cons.

Table of Contents

Why Do You Need To Invest In A Red Dot?

Before we dive into the Holosun 510C review, let’s first cover why it’s wise to invest in a red dot in the first place.

A red dot is designed to allow you to acquire a target faster than iron sights. This is why red dots are becoming an increasingly common sight (pun not intended) with law enforcement, tactical military units, competition shooters, and ordinary civilians alike.

Red dot optics utilize a single dot (which, yes, is usually colored red – but can sometimes be colored green or orange as well) that is placed on the same optical plane as the target. This permits a single point-of-focus, which is why targets are easy to acquire.

When you peer through a red dot sight, it will appear as if the red dot is ‘floating’ in the middle of the sight. This is because the location of the dot corrects itself depending on your angle.

In other words, regardless of what angle you are peering through the red dot from, your shots will hit where the red dot is aiming.

Most red dots are also non-magnifying, or zero power. However, they can be paired with magnifying devices if the shooter so desires. A red dot without magnification power, however, means that it’s suitable for close quarters shooting. Magnified optics, such as scopes, are not as ideal in these kinds of scenarios.

Another big advantage to red dots over iron sights is that they provide good visibility of the sight in dark or dim conditions. Whereas iron sights may ‘disappear’ in low light or overcast scenarios, the reticle remains highly visible so you can still properly engage the target.

Qualities To Look For In A Red Dot

Here are the top things to look for in a red dot sight:


The first quality to look for in a red dot sight is the basic design. There are two primary sizes of red dot sights: open and tube. Open red dots are a simple square-shaped design with a visible window. Tube red dots have all of the internal parts of the red dot housed inside the body. Between the two, open red dots offer faster sight acquisition, but are also more exposed to potential damage from the elements.

Reticle Size

The next quality to look for in a red dot sight is reticle size. As a golden rule, the smaller the reticle, the easier it is to make precise shots at longer ranges. However, larger reticles are easier to see and therefore faster to acquire the target in the first place.

The typical range in reticle size is 2-6 MOA. 

Battery Life

The longer your red dot can last on a single battery charge, the better. In general, the battery life of red dot sights is much higher now than it has been in the past. For example, it’s not uncommon now for red dots to last tens of thousands of hours on a single battery.


Last but not least, you must ensure your red dot is fully capable of withstanding the elements and any abuse that you put it through. This doesn’t mean you should purposefully abuse your red dot, but it does mean it needs to be ready to survive rain, sleet, snow, debris, or being thrown or knocked against hard surfaces.

This is why most red dots today are built out of highly durable materials such as aircraft-grade aluminum or titanium steel.

Now that we’ve covered why you should consider investing in a red dot over traditional iron sights and the top qualities to look for in one, let’s dive into what makes the Holosun 510C worth taking a look at.

Overview of the Holosun 510C

Based out of California, Holosun has been in the business of manufacturing red dots since 2013. They quickly gained a reputation for making high-quality red dots at competitive prices, and this has been the primary factor for why the company is so successful.

The 510C, in particular, comes with innovative features such as a long battery life, a quick detach mounting system, Shake Awake and Fail Safe technologies, and even a solar panel.

Let’s break down each of these features in greater detail:

Basic Design

The 510C is an open, fixed magnification red dot sight designed for use with rifles or pistol caliber carbines. It can be affixed to both Picatinny and Weaver rails with the quick detachment feature (more on this in a bit).

Total weight of the HS510C is just under eight and a half ounces, with dimensions of 4.75 x 3.62 x 3.12 inches.


The 510C comes with three reticle choices that you can alternate between: a 2 MOA dot, a 65 MOA circle, and then a combination (essentially the 65 MOA circle with the 2 MOA dot on the inside). There are ten different brightness settings, as well as two night vision modes.

Holosun designed the 510C to rely on solar power when exposed to normal light, while the backup battery activates in low light conditions. After a number of minutes of inactivity, the reticle automatically shuts off, but reactivates when motion is sensed.

Holosun HS510c MRS
The Holosun 510c offers a MRS (multi-reticle system) with 3 different options.


The glass of the 510C is designed to allow maximum light transmission while keeping glare to a minimum. This is accomplished thanks to the optical glass and multi-layer coating design.

Fail Safe Feature

The Fail Safe feature of the 510 means that the red dot remains powered even if the battery fails thanks to the solar power.

Holosun 510c Solar Cells
The solar cells are located on the back of the 510c and recessed to protect them from damage.

Shake Awake Feature

The Shake Awake feature is another neat aspect of the Holosun 510C: whenever the red dot senses even the slightest movement, it will instantly switch on thanks to its reliable motion sensor detection system. However, when the red dot goes without motion for a certain period of time (this time can be adjusted between ten minutes and twelve hours), it shuts off to conserve battery life.

The benefit here is that you can keep the 510C on at all times. If you want to keep your rifle or carbine in your safe or by your bedside as a home defense weapon, you’ll have peace of mind knowing that the reticle will instantly switch on as soon as you pick up the rifle.

Durable Construction

The 510C is built out of high quality, shock resistant aircraft grade aluminum. It’s designed to withstand recoil from repeated shooting and being knocked against hard surfaces such as rock or cement.

Long Battery Life

The standard battery life of the 510C is 50,000 hours on the sixth setting. On the maximum setting, this lifespan is reduced to 20,000 hours, which while less is still impressive in the industry.

The battery itself is a CR2032 model and is located on the side of the body. Removing the red dot from the rifle is not necessary in order to change the battery.

Quick Detachment Mounting

The Holosun 510C utilizes a quick detach mounting system, meaning that no tools are required in order to attach it or remove it from your Weaver or Picatinny Rail.

Furthermore, the 510C is designed to be used with backup iron sights as well, meaning that you can line up the iron sights through the red dot in the event that the reticle fails (or if you prefer to switch to shooting with the irons instead).

Manufacturer’s Warranty

The 510C comes with a limited lifetime warranty from the manufacturer for the first owner, and a five-year warranty for the optical glass. While admittedly not the best warranty in the industry, it’s still decent.

Range Report

Features and specs are great, but this review wouldn’t be complete without a true field test. That’s why I decided to take the Holosun 510C out on a range trip to really put it through the paces. The main goal for this trip was to test accuracy, reticle visibility in various lighting conditions, ability to hold zero when detached and re-mounted, and lastly to try out the 3 reticle settings to see which worked best for me.

The 510c was mounted on a budget build AR-15, equipped with a 10.5″ nitride barrel, so that was certainly considered when testing accruacy. As far as ammo, I brought Winchester .556 55 grain and Winchester 62 grain green tip. For the purpose of this test, I zeroed the red dot at 25 yards (read on to find out why I wished I had chosen 50 yards).

I took 30 shots at three different distances: 25 yards, 50 yards, and 100 yards and used a rest for the best possible test of accuracy.

25 Yards

I started my accuracy test at 25 yards. I was on target after about 10 rounds, using Winchester .556 55 gr. There was absolutely no challenge at 25 yards and I was putting shots through the same hole. The overhang at the range provided an ample amount of shade, so I kept the brightness setting on the low side, using the manual mode (no solar). I was easily able to pick up the reticle.

I almost immediately locked in on the 2 MOA dot with 65 MOA ring as the best reticle setting for me, looking particularly clear, even with astigmatism. At 25 yards, this worked perfectly, allowing me to put the ring around the whole target and the dot over the bullseye.

Holosun 510c at 25 Yards
Zero'ing and first shots with the Holosun 510c at 25 yards.

50 Yards

Grouping at 50 yards using Holosun HS510cAfter getting the Holosun HS510c sighted in, I took it out to 50 yards. My group started to open up a bit, but I was still hitting within 1″-1.5″ (yes with a couple of flyers).

Now, this is where I wished I had zeroed at 50 yards. You’ll notice from the image that I was starting to shoot a little high (and a tad left), even though my point of aim was on the bullseye. As you can probably imagine, this became an even bigger difference once I took it out to 100 yards.

I maintained the same reticle setting, however, it started to brighten up a bit at this point, so I switched to solar to see how that looked. The auto-brightness feature worked great and I was still able to see the reticle clearly, even with an extra bright background. At times, clouds would move over the sun and cause the lighting to change, but the reticle remained at an optimal setting for the environment.

Holosun HS510c at 50 Yards
Taking it out to 50 yards

100 Yards

Now, it was time to move one bay over where a buddy of mine had his 6″ steel plate setup at 100 yards. While I wouldn’t be going for pinpoint accuracy here, I knew that if I could ring steel at that distance, I would be happy. Just for fun, I also decided to try out the quick detach feature. I removed the red dot and re-mounted it, paying attention to the pic rail slots I was using previously. This would be a good test as to whether or not I would need to re-zero after a detach/re-mount.

For the last 30 rounds, I used Winchester 62 grain green tip (M855). Considering the fact that I was hitting about 2″ high at 50 yards, I held my point of aim toward the bottom of the 6″ steel plate. This seemed to put me right on target as I was able to hit the plate 28 out of 30 times. Just for reference, the majority of hits on the steel plate looked to be contained within about 3″.

It’s also important to note that I changed my reticle to the single 2 MOA dot, as the ring that I was using for reference at closer distances became way too large to help.

Holosun 510c at 100 Yards
Shooting a 6" steel plate at 100 yards

Pros and Cons of the Holosun HS510C

Here are the pros and cons of the Holosun HS510C:




The Holosun 510C is an impressive choice for a red dot. It offers a number of high-tech features commonly found only on more expensive models, offers two power sources, a clear lens, and a durable titanium construction. If you’re looking for a high-quality and long-lasting red dot that won’t break your wallet, the HS510C deserves your attention.

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