Holosun HS507C-X2 review: the sight everything else gets measured against

By the OpticVerdict Editorial Team.
Research-based review · Updated 2026-08-07

How we reviewed it: a research-based review built from the retailer specification sheet, the verified owner-review record of 461 reviews, and independent published testing. We have not bench-tested this unit ourselves; the score is our editorial opinion and owner ratings are shown attributed to their source. Where the retailer's own listing contradicts itself we say so rather than pick the flattering number. See how we evaluate.

What it is

The HS507C-X2 is Holosun's full-size open-reflex pistol dot: a 1x sight in a 7075-T6 aluminum housing on the Trijicon RMR footprint, with a top-mounted solar panel, a side-loading CR1632 and Holosun's Multi-Reticle System. It weighs 1.5 oz, measures 1.78 in long, gives you a 0.63 by 0.91 in window, adjusts in 1 MOA clicks with 50 MOA of total travel, and is IP67 sealed. The X2 is the third generation: matte finish, repositioned buttons, Lock Mode, and the side battery tray that the earlier versions lacked.

The reticle is the reason people buy it

The Multi-Reticle System lets you switch between a 2 MOA dot on its own, a 32 MOA circle on its own, or the two together, and because every reticle comes from the same emitter there is no shift in point of impact when you change. The dot is for precision. The circle is for speed, and it does something a dot cannot: if your presentation is slightly off, the edge of the ring appears at the side of the window and tells you which way to correct, so you stop hunting for a dot that is not there.

That is why instructors keep recommending it to shooters coming off iron sights, and it is also why it helps some shooters with astigmatism. Spreading the same light over a large ring instead of concentrating it in one point reduces the starburst effect that makes a plain dot look smeared. If that is your situation, the green HE507C-GR-X2 is worth considering too, since the eye is more sensitive to green and you can run it dimmer.

If you would never use the circle, note that you are paying about $47 for it. The HS407C-X2 is the same sight with a plain 2 MOA dot, and we compare them line by line in 407C vs 507C.

Solar, Shake Awake and the side battery tray

Three features work together here and they are the practical case for the sight. Shake Awake sleeps the reticle when the gun sits still and wakes it on the slightest movement, so the 50,000-hour rating is realistic instead of theoretical. Solar Failsafe runs the reticle off the top panel if the battery dies; reviewers have removed the cell entirely, taken the sight into sunlight and found the reticle still lit. And the CR1632 sits in a tray on the side of the housing.

That last one sounds minor and is not. The optic it was designed to compete with loads its battery from the bottom, which means unmounting the sight, breaking the thread locker and re-confirming zero at the range every time the cell dies. On the 507C you slide the tray out with the sight still bolted to the slide. For anyone maintaining more than one gun, that is the difference between a two-minute job and an afternoon.

“Shake awake, auto dim, ‘forever’ battery life, side door for battery replacement. It is a great reflex sight at a reasonable price.”

Most helpful positive review, via OpticsPlanet

Mounting: RMR footprint, but bring your own plate

The RMR footprint is why this sight fits so much. Any RMR-cut slide takes it, and so does any standard RMR-pattern offset or riser mount, which is what makes it a credible choice on an AR as a 45-degree secondary. What is not included is the mount: OpticsPlanet states "Mount Not Included", so budget a plate matched to your pistol's cut. Owners report clean installs across Glock MOS slides, a SIG P320 full-size with an EGW dovetail plate, a CZ Scorpion EVO and a Glock 19 Gen3 cutout.

The limit is width rather than pattern. This is the full-size C body, and on slim subcompact slides it overhangs. One owner running a Glock 34 notes the housing sits very slightly wider than the slide even there. If your pistol is a Glock 43X, a SIG P365 or a Hellcat, this is the wrong shape and the narrower K-footprint sights are what you want; we cover that choice in 407K vs 507K.

“Mounted the Holosun HS507C-X2 on a Sig P320 Full Frame with standard rear dovetail sight. Removed rear sight and replaced with the EGW #49518 mounting plate and attached the Holosun without any modifications. With the HS507C-X2 installed it has allowed me to make my very best shots at 25 yards.”

GrizzlyB, verified owner (IN), via OpticsPlanet

The auto-brightness trap

This is the one design trade-off worth understanding before you carry it, and it follows directly from where the solar panel sits. In auto mode the reticle's brightness is set by the light hitting the top of the optic, which is the light above you, not the light on your target. Stand in a dim room or inside a vehicle and aim out into bright daylight and the reticle has been dimmed for the wrong scene, so it can disappear against a brightly lit target. The same thing happens when a weapon light throws bright backsplash in the dark. Published reviewers reach the same conclusion consistently: for defensive use, pick a manual setting and use Lock Mode to hold it. It costs nothing and removes the failure mode entirely.

What owners flag, plainly

Across 461 reviews the record is unusually positive, and several owners describe the sight holding zero through hard use, including one who has run Holosuns through multiple shooting courses on Glocks, Shadow Systems, Staccatos and Berettas. Three things still come up often enough to report.

The first is the battery-tray screw, which owners describe as small and easy to strip if overtightened. The second is country of manufacture: two separate owners raise that it is made in China, one of them listing it as his only complaint. That is a preference, not a defect, but it is a real reason some buyers choose differently and we would rather name it than hide it. The third is the most helpful negative review on the listing, which reports the centre dot failing after 500 to 700 rounds on a custom Glock 17, leaving only the ring. Our capture of that review is cut off at the point where the owner contacts Holosun, so we do not know how it was resolved and will not guess. What we can say is that the 507C listing does carry Holosun's Limited Lifetime warranty, which the 407C listing does not, and that a single emitter failure inside a pool of 461 reviews rated 4.8/5 reads as a minority outcome rather than the normal experience.

“The X2 version of the 507C has some great improvements over the original. The finish is now a matte black... The + & - buttons are larger and easier to use. Battery loading/replacement is very easy with the new side access battery tray. Most important is the faster reaction time of the automatic mode.”

Duggie wuggie, verified owner (MO), via OpticsPlanet, 10 of 10 readers found it helpful

Awards, stated precisely

The 507C series is often described as award-winning, so here is what we could actually verify. In 2021 the National Tactical Officers Association awarded a Silver rating with a score of 4.36 following law-enforcement field evaluation against its published criteria. That rating went to the Primary Arms ACSS Vulcan version of the HS507C-X2, which is a different reticle from the standard 2 MOA dot and 32 MOA circle model reviewed here, so we do not claim it for this one. Separately, Holosun Technologies was named Optics Manufacturer of the Year in the NASGW Appreciation Awards for 2024, which is recognition of the company rather than of this sight. We found no verified industry award for the standard 507C itself, and where we could not confirm an award to its awarding body we have left it out.

Trade-offs, plainly

• Open emitter. The LED sits exposed, so heavy rain, snow, mud or pocket lint on the diode can smear the reticle. For genuinely harsh duty use an enclosed sight such as the HE509T or the EPS Carry is the right class of tool.
• Auto-brightness reads the light above you rather than downrange, so it can wash out. Run a manual setting for defensive use.
• The X2 buttons are small and sit nearly flush, which makes brightness changes awkward with gloves or under stress.
• The battery-tray screw is small and owners have stripped it. Do not overtighten.
• No mount or adapter plate in the box, and the RMR footprint will overhang a slim subcompact slide.
• A 2 MOA dot covers roughly 2 inches at 100 yards, so for precise work at distance a magnified optic is the better tool.

Key specifications

The same listing carries four configurations. We card the red HS507C-X2 at around $230. The green HE507C-GR-X2 is around $260, and two Primary Arms ACSS Vulcan versions sit above them, red at around $290 and green at around $340. The ACSS versions replace the dot and ring with a 10 MOA chevron inside a much larger dashed ring; that is a genuinely different aiming system, not a trim level, and we have not reviewed it here.

Should you buy it, and what else to consider

• Buy it if your slide is cut for an RMR pattern and you want one sight that moves between a pistol, a PCC, a shotgun and an offset rifle mount without compromise.
• Save $47 with the HS407C-X2 (around $190) if you will never use the circle. Same hardware, plain 2 MOA dot.
• Go smaller for a slim carry gun: the K-footprint HS507K X2 keeps this reticle in a body that fits a P365 or a 43X.
• Go sealed if you need weather immunity: an enclosed emitter is a different capability, not a nicer version of this one. See best enclosed red dots.
• Go bigger for competition, where the HS507COMP trades the solar panel for far more glass.

FAQ

More: best red dot sights · 407C vs 507C · 407K vs 507K · best pistol red dots · best red dot for a Glock · best red dot for astigmatism.