Holosun SCS Dot Sight – My Experience

Sits low, eliminates adapter plates – and the need for battery exchanges

Holosun’s new SCS sight, mounted to an optics ready S&W M&P 9mm Compact Pistol (5-shot group fired from 25 yards). Excellent accuracy thanks to an aftermarket Apex Tactical barrel. The sight’s selectable 2 moa dot helped wring out its full potential.

The Holosun SCS dot sight is popular, and for good reason. If you’re wondering if it could be the right choice for you, consider my experience that I’ll detail below.

Commonly referred to as “miniaturized red-dot sights” – MRDS for short – today’s choices abound picking a winner can be tough. Beyond their various “footprints,” durability, reticle design and size are considerations, often along with co-witnessing. The latter refers to the height of the optical sight’s window and dot, relative to the firearm’s original sights. If both are still usable, the set of “irons” can provide insurance if a reticle suddenly dies.

But even with careful shopping, the proof is sometimes in the installation. A few MRDS versions that I installed turned out to be less than satisfactory through no fault of their own. My admittedly picky problems were related more to the firearms on which they were mounted. Case in point a fairly recent 2022 purchase. After perusing a number of small optical sights, I ordered a promising prospect for a new 9mm pistol, an S&W M&P 2.0 Optics Ready, 4-inch Compact model.

I’d been looking for a reasonably-sized MRDS that could accommodate battery exchanges without a dismount which sometimes results in loss of zero. Holosun’s side-loading 507-C fit this bill and, because its footprint (the design of its base) was compatible with the adapter- kit that shipped with the S&W OR Compact, its installation appeared to be a simple project.

Having tracked down the Holosun, I sorted through S&W’s adapter kit and located the correct plate, using its included chart. The next step was the removal of the slide’s cosmetic optics-cut filler (see photo) so the project could proceed. And overall, the outcome was deemed successful.

HS507C X2 Review

The Holosun co-witnessed nicely with the S&W’s optic/suppressor-height (tall) sights, visible in the lower portion of its lens. Powered by a CR1632 battery, the optical sight’s life is lengthy as is, but a built-in solar panel extends it even further. Also, the reticle can be programmed to shut off after a user-specified period of idleness (10-minute default-setting).

However, thanks to the 507’s “shake awake” feature, it will reactivate from the slightest movement. And three choices are available: a 32-moa circle, circle/dot, or a precise 2-moa dot.

So, what’s not to like? Well, maybe nothing – but sometimes small things can get under your skin. As it turned out size can matter. My sole gripe was a matter of scale. Of a comparable size to other such sights – like the Leupold DeltaPoint Pro on a second 5-inch M&P – the 507-C is a natural for a full-sized pistol.

But the S&W Compact turned out to be less “compact” with a standard-sized dot-sight mounted to its slide. Thus, when Holosun debuted a smaller version of the 507 series, my interest was immediately piqued.

Holosun SCS 507 Comparison
Comparison of the Holosun 507-C (mounted to the S&W Compact) to the SCS. The latter’s shallow deck provides just enough room for a windage dialbut don’t bother looking for a battery compartment.

Holosun SCS-MP2-GR

The new SCS retains many of the 507-C’s features but, beyond its smaller overall size, it sits lower. The reduced height is possible because the SCS mounts directly to the pistol’s slide – assuming it’s a suitable optics-ready version. Because slide-cuts vary by manufacturer, SCS choices will be limited to the strongest sellers. The two listings I stumbled on to were designed specifically for Glock MOS-series pistols and S&W M&P 2.0s.

I sprung for an SCS MP-2 GR (“GR” for green reticle), but ’ve since handled an SCS MOS model. Designed specifically for factory optics-ready Glocks, it appears to be almost identical with a bonus of matching slide serrations.


My SCS arrived nicely packaged, in a small box. Because it direct mounts, its contents were minimal. Foam slots contained the electronic sight, a basic T10 Torx wrench/sight adjustment tool, two mounting screws, a lens clot, and small set of clear directions.

Holsun SCS Packaging
The SCS un-boxed. The contents are minimal because the mounting process is simple. Note the solar panel on the deck of the optical sight. Its three selectable reticle (green) options are illustrated on the sleeve. The small control pad is also visible near the sight’s rear edge.

The SCS is operated by just one small push-pad on the left side of its housing. It’s the gateway to three reticle options (similar to the 507-C) which, for this version, are green instead of red. So, scratch the usual MRDS reference. Maybe MRGDS instead?

The housing of the SCS MP-2 is milled from 7075 aluminum (whereas the Glock-MOS version is claimed to be a Titanium alloy). Advertised as “IP 67 waterproof”, the most prominent feature is the solar panel on its deck.

Elevation and windage can be adjusted by a pair of flush-mounted dials. Surrounded by 1-moa scales, their corresponding clicks are distinct, and both can be accessed in close proximity to a rear sight.

Solar Dependency

Beyond the elimination of extraneous mounting hardware, the SCS can sit low because it lacks a normal battery compartment – or even the means to install one. SCS apparently stands for “solar charged sight,” the source of its renewable power. Run time is claimed to be near-endless and, supposedly, even brief periods of sunbathing will rejuvenate its internal battery.

Co-witnessing & Size

Because of its shallow deck, co-witnessing should be possible with many standard-height sights. No searching for a matching adapter plate either; “direct mount” means just that. Being model specific, the SCS fastens directly to an optics-ready slide via the two included screws. As mounted to my M&P 2.0 Optics Ready Compact, the bottom edge of the lens sits a scant 0.100” above its slide (0.240” for the 507-C).

Holsun SCS 507 Heights
Holosun SCS (L) and 507-C height comparison. Both are mounted to S&W M&P Optics Ready Pistols. Either will co-witness with the tall factory-issue sights but, because the SCS direct-mounts to the slide without an adapter plate, it sits much lower. As such it’s more iron-sight friendly.

From its bottom to the lower edge of its lens, my SCS MP-2 measures an ultra-shallow 0.200”. The dot sits at .540”. The window is a smallish 0.58 x 0.77 inches. Overall length is about 1.980”. Width is about one inch. It weighs a feathery 1.3-ounce.

Installation, Zero, & Operation

If you’re starting from scratch, simply remove the slide’s filler-plate to expose the pair of threaded holes corresponding with the SCS. The included screws are pre-coated with a blue thread sealant but, playing it safe, I applied an additional dab to each. Also, instead of using Holosun’s tool, I followed their recommendation and used a torque wrench (T10 bit), set to 15 inch-pounds. The process almost seemed too simple – right down to the zero process.

Holosun SCS Footprint Slide
Mating surfaces of an S&W OR slide (filler plate removed) and the “footprint” of the Holosun SCS. The mounting screws shipped with the optical sight, pretreated with blue thread sealant. Pretty simple system.
Holosun SCS Install
The SCS ready to install, using a T10 bit and torque wrench set to the recommended 15 in-lbs. The bottle of blue thread-sealant is there for extra insurance.


Holosun says the sight “has been factory zeroed to approximately 25 yards”. Comparing the M&P’s sights to the dot on a 12” bore-sighting target, both looked darned close, so I left the windage and elevation settings alone pending the range session.

Live-fire commenced using the precise 2-moa dot setting. The first three rounds, fired from 25-yards off sandbags, produced a tidy group at 2:00, approximately 2 ½-inches from my aiming point. From there, using the Holosun tool, it was just a matter of counting clicks. At 25-yards each 1-moa click translates to ¼” of adjustment. Following the directional arrows, 12 clicks per dial produced a well-centered group. That was pretty much it. Full range of adjustment is advertised as 30 moa per dial – approximately 30-inches at 100 yards.

Of course, beyond precise sight adjustments, zeros come more easily with accurate firearms. The above process was a breeze thanks to the M&P’s aftermarket barrel, an Apex Grade version (installed by yours truly).

Using the “Multi Reticle System”

A one-second press of the push-pad powers up the SCS to display its “default” setting, the first of three available reticles:

Circle & dot: The default reticle is a “large” 32-moa circle surrounding a fine 2-moa dot.

Dot only: A subsequent 1-second press produces the 2-moa dot alone, the better choice for precise shot placement and/or reduced power consumption.

Circle: A third press produces the 32-moa circle with its four “positioning points.”

Turning off the sight requires cycling it through all the three reticle settings. The fourth one-second press turns it off.

SCS Resolution

The reticle’s intensity is auto regulated by a built-in sensor. I experienced no difficulties resolving the 2-moa dot in mostly sunny conditions against white silhouette targets. But to gain a brighter reticle, 30-minute increases can be acquired via momentary pad depressions.

Indistinct reticles and/or flaring seem to be common dot-sight maladies. I normally need a set of basic OTC reading glasses to achieve a clear dot but, happily (for me anyway), the SCS worked in reverse. Sans glasses, slight flaring was replaced by a crisp green dot – good news since I don’t wear readers while wandering about.

Being somewhat red color blind, the green reticle was an anticipated plus but, actually, it took a bit of getting used to – probably due to years of red-dot experience. Quick transition though.

The bigger issue may be a “busy” image, especially with the dot/circle – my initial take due to the smallish lens and set of suppressor-height iron sights. I had little interest in the circle settings – at first. But they turned out to be smokin’ fast on steel silhouettes at combat distances. That said, the dot remains my preference. And the iron sights were soon tuned out – as they should be. Rather than attempt to float the dot on the front sight, just place the dot on the target and press the trigger.

Power Expectations

One thing I failed to note during the purchase was the absence of an auto-shutoff/shake-awake feature (per the 507-C). A detailed chart in the manual covers power consumption but, being technically challenged, I’ll offer Holosun’s shorter version: “During normal use there is virtually no need to worry about battery power consumption”. Claimed run time is 20,000 hours using only the battery’s reserve.

Also, the plain dot consumes less juice – only about one third that of the circle & dot. In any case, low-battery warnings appear with ample time for a solar recharge, beginning at 30 % remaining power (single flashes/one second intervals). But, at some point in the distant future, the internal battery will lose its pizzazz – and that will require a trip back to Holosun for a free replacement.

SCS Pros and Cons

Cons include a possibly busy image (for some), and the lack of an auto-shutoff. And again, an eventual trip back to Holosun for a replacement battery.

Pros? The SCS is easy to install and zero. Size wise, it doesn’t overwhelm a handgun, and its minimal mass may contribute to more positive pistol function. Also, it comes with a “limited Lifetime Warranty” that covers problems short of negligent abuse.

Parting Shots

Holosun SCS 507 Pair Pose
A matter of scale: S&W M&P 4″ Compact (L), equipped with Holosun’s SCS. The 507-C is a nice match for the full-size 5″ M&P C.O.R.E. Both S&Ws are 2.0 versions with optics-ready slides – a requirement for the direct-mount SCS.

Because the SCS is a direct-mount system its availability will be limited to popular handguns. As of May 2023, beyond full-size Glock MOS and M&P 2.0s, it’s offered for the SIG P320, Walther PDP 2.0, and H&K’s VP-9 – all featuring optic-cut slides.

On the other hand, its bigger brother, the 507-C, can be mounted to many of today’s handguns. Mine turned out to be a good match for my larger S&W 5-inch 9mm Performance Center C.O.R.E. (Competition Optics Ready Slide).

Because this PC M&P shares the same OR slide cut as my Compact, the switch was a cinch. The 507-C did require an adapter-plate, but the S&W kit contained a match (#1). Aesthetics aside, the 507-C also has a larger window. So, overall, it’s a better pick for a standard-size pistol. The larger 507-C also offers additional features related to reticle intensity, shut-off delays, etc. Then again, the same can be said for a number of competing optics…

Holosun SCS 507 Mounting
Conventional MRDS mounting process: This example shows an S&W M&P 2.0 OR slide with its filler plate (top) removed. The adapter plates and screws shipped with the pistol. The plate (#1) in the foreground will provide the necessary connection for the Holosun 507-C. Most of today’s competing systems use similar designs. But some combinations can be more like puzzles.

More Dot-Sight Madness?

The above S&W PC M&P 5” 2.0 started off with a Leupold DeltaPoint Pro – a quality MRDS. But (being picky again) despite its tall factory sights, the Leupold’s thick deck (0.500”) precluded their use – the main reason I swapped it out for the Holosun 507-C.

However, the DeltaPoint Pro wasn’t homeless for long. It’s presently mounted to a 6-inch S&W Model 686 .357 Magnum hunting revolver – which, of course, required a different adapter. The solution, Leupold’s DP/S&W Classic Mount, replaces an S&W’s rear sight. Its obstruction is thus rendered moot, but the system is more than satisfactory. The DP-Pro also eliminated a battery-exchange hassle related to the S&W’s predecessor; a still-serviceable but older bottom-loading Burris FastFire.

Meanwhile, I’m sitting on a surplus dot-sight and Weigand/S&W base. Both will no doubt be repurposed, but the SCS sure does seem like a simpler alternative to these dot-sight shenanigans!

Source link: https://survivedoomsday.com/holosun-scs-dot-sight-my-experience/ by Steve Markwith at survivedoomsday.com