The Holosun HS510C Reflex Sight is one of the most competitive sights in its class. It has more features and incredible durability for half the price as some of the most popular optics available. This puts the 510C at the head of the pack for many shooters. Outpacing the budget optics and even many of the more expensive ones, makes this an excellent choice for rifle and carbine applications.
In this Holosun 510C review, we will cover the specifications and top features of this optic in as much detail as possible, going in-depth to look at the benefits this optic has to offer shooters. We’ll see what some other shooters have to say and answer some of the more common questions asked about this Red Dot Sight (RDS).
Holosun HS510C Review
The Holosun 510C is an open reflex style red dot sight machined from lightweight aluminum. This optic weighs 4.94 ounces measuring 3.3 (in) x 1.68 (in) x 1.78 (in). Target acquisition is achieved effortlessly through a crystal clear .91 (in) x 1.26 (in) viewing window.
The 510C comes standard with Holosun’s multi reticle systems. The optic operates on a single A 3-volt lithium coin cell, 16mm across, holding about 120 to 140 mAh. It powers many micro and subcompact pistol optics that trade runtime for a smaller footprint.Full comparison → lithium coin battery providing an estimated 50,000-hour battery life using the mid-brightness setting. Price and quality make the Holosun 510C an excellent red dot sight option for rifle, carbine, and shotgun for close quarter short-range engagements.
Established in 2013, Holosun quickly set a track record for designing and manufacturing competitively priced optics with innovative features that often beat out the competition. Headquartered in Walnut, California, Holosun is known for pushing the envelope with operator level quality and reliability, without the price. The Holosun 510C is a testament to this value, delivering on that promise of quality and affordability.
Primary Features of the Holosun HS510C
Design
The reflex sight is manufactured from aluminum, making it lightweight and durable. This is accompanied by a A premium housing metal that is stronger than either aluminum grade and effectively corrosion-proof, with excellent strength-for-weight. Found on high-end enclosed optics like the Holosun 508T and 509T.Full comparison → hood for the sight window, adding an extra layer of protection. It weighs just 4.94 ounces with the battery installed.
The 510C boasts an A high-voltage process that grows a thick, hard, partly crystalline ceramic oxide on aluminum or titanium, tougher than conventional anodizing.Full comparison → (Micro Arc Oxidation) surface treatment finish to even further reinforce the frame of the optic. This helps it to withstand greater impact and heat, giving it up to twenty times greater resistance to degradation.
With an A full IP code meaning dust-tight (first digit 6) plus temporary immersion to 1 meter for 30 minutes (second digit 7).Full comparison → rating, the optic resists water intrusion at a depth of one meter for up to half an hour. The HS510C will withstand inclement weather and other high moisture environments, meaning that water damage is unlikely for most users.
The Holosun measures at 3.3” x 1.68” x 1.78”, making it longer than some other RDS optics, but not so large that it is overly heavy or unwieldy. The sight window is .91” x 1.26”.
The optic incorporates an incredibly useful solar panel failsafe, extending battery life potentially well beyond the max battery life of fifty thousand hours. The failsafe can power the sight when batteries are not available as long as there is some ambient light present, making this an ideal optic for survivalists and duty use.
Reticle
The Holosun 510C comes with three different reticle selections. You have the option of a 2 MOA (Minute of Angle) reticle, a 65 MOA circle, or the 65 MOA circle with the 2 MOA dot inside. Many shooters report that the 65 MOA is most helpful in a home defense scenario, allowing the shooter to see through the reticle for easier target confirmation and acquisition.
The 2 MOA dot may be more suitable for mid to long-range engagements. Reticle choice is really a matter of shooter preference, so you can use the setting you are most comfortable with.
The optic has a total of 12 brightness settings, 10 of which are various levels of brightness for daytime use. The sight has 2 different brightness settings for use alongside a night vision system as well.
The default reticle setting is both the 65 MOA circle and 2 MOA dot. To cycle through the reticle options the user must hold down the (-) button for three seconds.
The sight is powered by a single A 3-volt lithium coin cell, 20mm across, and the most common red dot battery (about 210 to 240 mAh). Stocked almost everywhere, so a field swap is easy.Full comparison → battery. The battery tray is located on the side of the optic, so there is no need to remove the optic to change the battery.
The Holosun uses motion sensor technology that will power down after 10 minutes of no movement and will wake back up at the last brightness and reticle settings prior to engaging sleep mode.
The elevation adjustment screw is located at the top of the optic, while the windage adjustment is on the right side. Adjustments for the windage and elevation on the 510C are .5 MOA per click, with an adjustment range of +/- 50 MOA.
Mounting
The 510C comes with a quick-release mounting system that can be mounted to any standard Picatinny rail system and without tools. This allows the sight to be easily mounted or detached from your weapon system, giving you the option of quickly switching to another optic or moving the optic to another shooting platform.
Details
Included with your purchase:
- Holosun HS510C Reflex Sight
- Absolute Cowitness QD Mount
- T10 L Key
- User Manual
- CR1632 Battery
- Lens Cloth
Reliability standing
Holosun HS510C (open reflex, 2 MOA dot / 65 MOA circle)
Medium confidence based on 4 sources, 3 first-hand.
- Rounds tested
- thousands
- Battery
- CR2032: One first-hand competitor reported never replacing the CR2032 across three years of regular IPSC use, though he attributes part of that to the solar backup and is uncertain how much was battery versus solar. This is an in-use observation, not a controlled runtime measurement.
What those tests were
- drop: pass . Reviewer dropped the optic and host CZ Scorpion onto a concrete porch during testing with no loss of zero and no functional failure (hundreds of rounds fired, 5/5 reliability).
- drop: pass . Mounted on an ASP training gun and dropped a few times; only damage was finish abrasions, zero was not lost across the test.
- submersion: pass with caveat . Incidental wet-weather exposure only, not a sealed-submersion test. First use was a cold, somewhat rainy day with no issues from wet or cold, and the optic 'soaked up a few drops without losing zero or failing.' Light rain only; no heavy-rain or true submersion test was performed first-hand.
- recoil endurance: pass . Three years and thousands of rounds of IPSC PCC use (training, local matches, Nordic Championships, 2025 World Shoot); 'held its zero flawlessly from the start' and never failed even as other PCC components broke during competition.
Aggregated from others' first-hand testing, not our own: this standing deliberately reaches past any one shooter's round count. We surface a sourced reputation tier rather than inventing a score the evidence cannot support.
Full reliability data →Warranty standing
Holosun warranty
Lifetime housing, 10-yr electronics, non-transferable
- Housing
- Lifetime
- Electronics
- 10 yrs
- Transferable
- No
- Receipt required
- Yes
- Registration
- Yes
- Support
- active
Holosun tiers coverage by use. Standard consumer models are warrantied for "normal, personal use" only; using them professionally (duty/LE/commercial) voids the manufacturer's warranty. Professional-designated models are marked with an "LEM" suffix in the model number and carry a 3-year warranty from date of purchase (unless otherwise specified by individual contract terms). This LEM-suffix designation is stated on the official holosun.com/warranty page.
FAQ
Does the solar panel recharge the battery? No, the battery is not rechargeable. The solar panel serves as a secondary power system that the optic will default to when possible to conserve battery life.
Is the Holosun 510C a holographic sight? Technically the Holosun HS510C reflex sight is not a holographic sight like the EOTECH 512. A reflex sight uses a LED and an objective lens to reflect the reticle, while a holographic sight uses laser diodes and mirrors to project the reticle.
Are Holosun sights made in China? Holosun is an American company but does have some sights and components manufactured outside the US including China.
Customer Feedback
The Holosun 510C has 334 customer reviews with an average customer rating of 4.7 out of 5 stars on Amazon.com. Eighty-six percent of customer reviews are 5 stars.
Quality: “The very best reflex sight on the market today. Doing a side by side comparison with an Eotech will hold Parallax perfectly.”
Price: “This sight is currently on my Rem 870, and can handle shotguns. Compared to an Eotech at this price, I enjoy this more.”
Accuracy: “It’s a great sight for the money. The lever attachment system is very convenient and I am very satisfied with its accuracy.”
Pros & Cons
Pros
- Excellent battery life ranging from 20,000 hours on highest to 50,000 hours on lowest setting
- Easy to access battery compartment on the side -- no need to remove optic
- Shake awake motion-sensing technology extends battery life and ensures readiness
- Very large viewing window (.91" x 1.26") for enhanced situational awareness and target acquisition
- Three reticle options (2 MOA dot, 65 MOA circle, or combination) for various shooting scenarios
- Solar panel failsafe can power the sight indefinitely without battery in proper lighting
- IP67 waterproof with incredibly strong aluminum/titanium MAO-treated frame
- Quick-release mounting system -- no tools required
Cons
- On the heavier side at almost 5 ounces
- Holosun limited lifetime warranty only covers structural makeup -- optical system covered for 3 years only
- Not the cheapest option -- alternatives like the Sightmark Ultra Shot offer similar performance for less
Variations and Alternatives
Variation: The 510C can be purchased with a green reticle. The HE510C-GR model is part of the Holosun Elite series with titanium construction and Holosun Elite Warranty.
Alternative: One of our favorite sights in this class is the EOTECH EXPS3. For a cost-wise solution, you can opt for the Sightmark Ultra Shot M-Spec.
