Glock 43X MOS Red Dot: Ultimate Guide to Sights, Compatibility & Features

The Glock 43X MOS is a favorite for concealed carry, and with a red dot sight, it gets even better. Pick the right red dot, and you’ll notice faster target acquisition, sharper accuracy, and easier aiming—whether you’re out in the sun or in a dim room. But not every optic fits like a glove, so it’s worth figuring out which models actually work with the Glock 43X MOS.

Whether you’re new or have plenty of range time, picking a red dot comes down to size, battery life, and how well the sight locks onto the slide. Glock cut the 43X MOS slide for micro red dots, so you’ll want a sight with the correct footprint. Ruggedness, reliability, and simplicity matter, especially if you’re carrying it every day.

There are lots of solid red dot options for the Glock 43X MOS. People often recommend the Holosun 507K X2, Shield RMSc, Swampfox Sentinel, and Crimson Trace RAD Micro Pro. These are known for their clear sight pictures and tough builds. You can check out more choices and see what makes each one unique in this in-depth list of Glock 43X MOS red dot sights.

Key Takeaways

• The Glock 43X MOS works best with red dots that match its slide cut.

• Optic durability, footprint, and battery life matter most for everyday use.

• Choosing the right red dot sight improves speed, accuracy, and confidence.

Overview of Glock 43X MOS and Red Dot Integration

The Glock 43X MOS is a slim, optics-ready handgun that lets you quickly install micro red dot sights. Add a good optic, and you’ll likely see improvements in accuracy, speed, and confidence—whether for daily carry or home defense.

What Is the Glock 43X MOS?

The Glock 43X MOS is a compact 9mm pistol built for folks who want something easy to conceal and dependable. It’s got a slim profile, ten-round mag, and the GLOCK Marksman Barrel for a bit more precision.

This model includes a Modular Optic System (MOS) cut on the slide, set up to accept micro red dot sights—mainly those with the RMSc footprint. That means you can add optics without sending your slide out for custom work, which is a big plus for concealed carry fans.

The 43X MOS stays lightweight and thin, so it’s comfortable to carry all day. There’s also a rail for lights or lasers, adding some flexibility if you want to customize further.

Benefits of Adding a Red Dot Sight

Slapping a red dot sight on the Glock 43X MOS brings some clear perks over old-school iron sights. Red dots make it faster to pick up the target because you just need to find the dot—no lining up front and rear sights. That’s a big help for speed and accuracy, especially if you’re in a rush or under pressure.

Red dots shine in low light or if your eyes aren’t what they used to be. The bright dot pops out, making close or even longer shots easier. Most modern micro red dots have long battery life, side-loading trays, and tough construction to handle daily bumps and scrapes.

Options like the Holosun 507K X2 and Shield RMSc offer multiple reticles, waterproofing, and shake-awake features—so they’re reliable and easy to live with. If you want to dig deeper into models and features, check out the best Glock 43X MOS red dots.

Impact on Concealed Carry and Everyday Use

For concealed carry, a red dot can make drawing and aiming noticeably quicker. The Glock 43X MOS’s slim shape and light weight make it easy to carry discreetly, even with an optic on top. The right red dot keeps the pistol’s profile low, so it’s less likely to print under a shirt.

Red dots on small pistols like the 43X can speed up your first shot and tighten up your follow-ups. If you’ve got a good co-witness between the optic and factory-height iron sights, you’ll have a backup if the dot ever gives out.

Most popular models use the RMSc footprint, so picking a compatible optic is pretty straightforward. Reliable picks like the Holosun EPS Carry, Shield RMSc, and Swampfox Sentinel offer solid battery life, weatherproof housings, and shock resistance. If you want more details about how the MOS platform works with red dots, check out this Glock 43X MOS red dot compatibility guide.

Red Dot Footprints and Compatibility

The Glock 43X MOS has a specific footprint for mounting red dot sights. It’s worth understanding this footprint and which optics fit directly before you buy anything.

Understanding RMSc and RMSc Footprint

Glock built the 43X MOS with a slim slide for micro red dots. Its mounting system uses the RMSc footprint (sometimes written as RMS-C).

Shield Sights created the RMSc footprint for tiny pistols. It’s got two mounting posts up front and uses small screws. Most compact optic brands now make red dots that fit this standard.

The RMSc footprint isn’t the same as RMR or Docter footprints you’ll see on bigger pistols. Those won’t fit without an adapter. Always check that the optic’s box or website says “RMSc compatible.” Picking the right footprint saves you the headache of extra plates or custom work.

Red Dot Sights That Fit the Glock 43X MOS

Only micro red dots with the RMSc footprint will fit the Glock 43X MOS without an adapter plate. Some solid choices:

• Shield RMSc: The original, fits perfectly

• Holosun 507K/407K and EPS Carry: Both mount right up and are known for durability

• Swampfox Sentinel: Slim and a direct fit

• Sig Sauer RomeoZero: Usually fits, but double-check your slide for quirks

• Trijicon RMRcc: Made for slim slides, but you might need a special mounting kit

You’ll find a detailed list of compatible optics and fit notes at this comprehensive guide. Stick with these RMSc footprint optics for direct mounting on the 43X MOS.

Adapter Plate Considerations

If your optic doesn’t use the RMSc footprint—like the bigger Trijicon RMR or Leupold DeltaPoint Pro—it won’t bolt straight onto the Glock 43X MOS slide.

You can get adapter plates for some models, but adding a plate raises your red dot higher above the slide. That can slow down how quickly you find the dot, and it might make using iron sights as backups a pain.

Since this pistol is all about being slim and easy to carry, keeping the optic as low as possible just makes sense. Go with an RMSc footprint red dot for the best fit and feel. Plates? Only as a last resort if you’re dead set on a specific optic.

Best Red Dot Sights for Glock 43X MOS

Finding the best red dot sight for the Glock 43X MOS really matters if you want faster target acquisition and tighter groups. The best options give you clear reticles, dependable performance, and a slim fit for concealed carry.

Holosun HS507K-X2

The Holosun HS507K-X2 is a go-to for the Glock 43X MOS because of its compact size and handy features. It’s got a multi-reticle system, so you can pick a 2 MOA dot, a 32 MOA circle, or both. That flexibility helps for both up-close and longer shots.

The side-loading battery tray lets you swap batteries without removing or re-zeroing the sight. Expect up to 50,000 hours of battery life—about five years if you’re not leaving it on 24/7. The Shake Awake motion sensor shuts the sight off when idle, saving juice.

Holosun built it from 7075 T6 aluminum, so it shrugs off drops and daily wear. Its low profile keeps the pistol slim—ideal for concealed carry. If you add a Holosun 507K with the right adapter, you’ll get a secure, no-fuss fit on the Glock 43X MOS.

Shield RMSc

The Shield RMSc stands out for its ultra-slim design, made just for single-stack pistols like the Glock 43X MOS. It mounts directly to the slide, no overhang, so your gun stays as slim as possible for deep concealment.

This micro red dot uses a tough aluminum body and a polymer lens for extra durability. The lens handles hits better than glass and gives you a clear, parallax-free view. You’ll get two or three years from a single CR2032 battery.

Choose from a 4 or 8 MOA dot. Most folks like the 4 MOA for its balance of speed and precision. The Shield RMSc is still a top pick if you want a light, no-hassle optic for your Glock 43X MOS.

Trijicon RMRcc

The Trijicon RMRcc is known for being tough as nails and slim. Trijicon made it for single-stack pistols, but most Glock 43X MOS slides will need to be milled or swapped for a custom slide to make it fit.

Its reinforced housing and solid electronics let it take a beating. You can pick a 3.25 or 6.5 MOA dot, so you can dial in speed or accuracy. The battery runs two to three years on a CR2032 cell.

One cool perk: its “lock-out” mode keeps you from accidentally changing the brightness, which is handy for daily carry. Shooters who want max reliability often rate the Trijicon RMRcc highly for the Glock 43X MOS, even if it takes a bit more work to install.

Swampfox Sentinel

The Swampfox Sentinel gives you solid performance without breaking the bank. It’s made from 7075 T6 aluminum and bolts right onto the Glock 43X MOS slide—no drama there.

You can choose manual or auto-brightness models. The Shake ‘N Wake feature saves battery by powering down when still and waking up with movement. The 3 MOA dot is quick to pick up but still small enough for careful shots.

The lens frame is a bit thinner than pricier optics, but it keeps things light and the gun’s profile low. Plenty of owners say the Swampfox Sentinel is a great starter red dot if you want to try a micro optic without spending a fortune.

Key Features to Look For in a Glock 43X MOS Red Dot

When you’re picking a red dot for the Glock 43X MOS, focus on toughness, battery life, how easy it is to see the reticle, and how simple the adjustments are. Little details matter a lot for reliability and how much you actually enjoy using it.

Durability and Housing Materials

The best Glock 43X MOS red dots use strong housings. Look for sights made from 7075-T6 aluminum or carbon-infused polymer. Both materials handle drops and everyday knocks well. 7075-T6 aluminum is especially good for rough use and recoil. Carbon-infused polymer is lighter but still tough enough for most people.

Try to find an optic with multi-coated lenses—they cut glare and boost clarity, whether you’re outside or in low light. Lenses with anti-reflection grooves also help keep annoying reflections out of your sight picture.

Sealing matters too. Water and dust resistance keep your red dot running in the rain or when things get gritty. Unlimited eye relief and a wide field of view help you get on target fast, no matter how you’re holding the pistol.

Battery Life and Power Type

Battery type and life make a big difference in reliability. Most popular red dot sights for the Glock 43X MOS use either a CR2032 or CR1632 battery. CR2032s are easy to find just about anywhere, while the CR1632 is smaller and fits better in compact optics.

Long battery life is a huge plus. Some red dots run over 50,000 hours on one battery. Features like Shake Awake help by turning the sight off when it sits still and snapping it back on with movement.

It's a relief when you can swap the battery without taking off the sight. Side-loading battery trays make this much easier, so you don’t lose your zero. Some models add a lock mode to keep you from accidentally bumping the power settings while carrying.

Brightness and Reticle Options

Brightness control really matters for quick target acquisition. A lot of sights offer both automatic and manual brightness settings. The auto mode uses sensors to match the dot’s brightness to your environment, but sometimes you just want to set it yourself. Manual controls let you do exactly that, whether you’re out in the sun or tucked away in the shade.

Reticle type changes how the sight feels. Most red dots use a 3 MOA or 3.5 MOA dot, which strikes a nice balance between speed and precision. Some optics let you pick between different reticle shapes—like a circle-dot—depending on what you’re doing.

Some reticles are made for speed, others for fine aim. Good brightness settings and smart reticle design work together to keep the dot visible and usable, no matter the light.

Adjustment and Controls

Easy adjustments make a world of difference when sighting in a Glock 43X MOS red dot. Tool-free windage and elevation dials let you zero the sight quickly—just use your fingers or a coin. That’s handy at the range or out in the field.

Controls should be simple and dependable. Big, easy-to-reach buttons for brightness, lock modes, and reticle changes are best, and you don’t want them snagging or moving by accident. A lot of the newer optics let you lock out controls so nothing gets bumped during concealed carry.

Good sights hold zero from shot to shot. Audible or tactile clicks for windage and elevation help you dial things in more precisely. This makes it easier for both new and experienced shooters to stay on target and feel confident in their setup.

You can check out more details on top features and models in red dot reviews at Red Dot Shooters and BadAssOptic.

Performance and User Experience

Picking a red dot sight for the Glock 43X MOS is really about how much it helps you shoot better and react faster, while still holding up to daily use and being easy to maintain. Shooters want to trust their optics in any situation and not have to fuss with them.

Accuracy and Target Acquisition

A good red dot sight makes aiming easier by putting a clear dot right where you need it. Sights like the Holosun HS507K-X2 and Trijicon RMRcc help shooters get on target quickly, especially when things get stressful.

The best red dots come with a bunch of brightness settings. This way, you can see the reticle in full sun or in low light. A crisp dot or circle-dot reticle helps you pick up the target faster. Some, like the Holosun, let you swap between reticle types, which adds flexibility for different shooting needs.

Competitive shooters and folks who carry for self-defense both appreciate how these optics speed up sight alignment and boost precision. Honestly, anything that cuts down the time it takes to aim can make a real difference in high-pressure moments. For more on red dot accuracy and what’s out there, check out this list of the best red dots for Glock 43X MOS.

Reliability in Different Conditions

Reliability comes down to both battery life and how tough the optic is. Top models have waterproof and shock-resistant housings. The Trijicon RMRcc, for example, is waterproof to 20 meters, and the Holosun HS507K-X2 has an IP67 rating.

Manufacturers use 7075-T6 aluminum or carbon-infused polymer for durability, so these sights can take a few knocks. Long battery life—like 50,000 hours on some Holosuns—means you don’t have to stress about it dying at the wrong time.

Controls need to work in the cold, rain, or heat. Some models include back-up iron sights or rear notches, so you can keep shooting even if the optic goes down. That’s a big deal for anyone carrying the Glock 43X MOS in unpredictable conditions.

Ease of Installation and Maintenance

Installing a red dot sight on the Glock 43X MOS is usually quick, thanks to its RMSc footprint. Most new sights just bolt on—no extra plates or adapters—so even first-timers can get it done fast.

Battery access matters, too. Some optics, like the Holosun HS507K-X2, have side-loading trays, so you can swap batteries without removing the sight and messing up your zero.

Maintenance is mostly about keeping the lens clean and checking the battery. Lenses with polymer or hydrophobic coatings are easier to wipe down and less likely to scratch. Straightforward controls and easy adjustments mean you spend more time practicing and less time fiddling with gear. For a closer look at installation, see these Glock 43X MOS red dot sights.

Summary: Choosing the Right Red Dot for Your Glock 43X MOS

Finding the right red dot for the Glock 43X MOS really comes down to fit, reliability, and how you plan to use it. You’ll want to think about what you need—reticle size, battery life, and whether you need an adapter plate all play a part.

Top Recommendations by Use Case

If you’re carrying concealed, the Holosun 507K X2 stands out. It’s tough, has a long battery life, and gives you a choice of reticles. People like how compact it is and features like Shake Awake, but keep in mind you’ll need an adapter plate since the Glock 43X MOS uses the RMSc footprint. For a sight that fits right on, the Shield RMSc is easy to install and is a favorite for its always-on feature and compatibility. If you’re on a budget, the Holosun 407K is a solid pick with a single 6 MOA dot and a lower price.

For range days or competition, the Trijicon RMRcc brings excellent durability, 10 brightness settings, and a choice of 3.5 or 6.5 MOA dot. Like the Holosun, it’ll need an adapter plate. The Swampfox Sentinel and Crimson Trace RAD Micro Pro both fit directly and offer good durability and clear reticles. For more comparisons, check the top Glock 43X MOS red dot sights.

Final Thoughts on Upgrading Your 43X MOS

Double-check the optic’s footprint before you buy. The Glock 43X MOS comes with an RMSc cut, so sights like the Shield RMSc, Swampfox Sentinel, and Crimson Trace RAD Micro Pro go right on. Others, like the Holosun K-series or Trijicon RMRcc, need an adapter plate.

Battery life, brightness controls, and reticle type should all factor in. If you want speed for defensive shooting, a bigger or multi-reticle dot can help. For more accuracy, go with a smaller MOA. Build quality matters, whether you’re carrying or hitting the range. For more info, check out reviews of the best red dots for Glock 43X MOS.

Frequently Asked Questions

The Glock 43X MOS uses the Shield RMSc footprint, which limits direct-fit red dots. Some brands need special mounting steps or adapter plates. Many sights offer features like quick battery changes and different reticle styles for more flexibility.

What are the compatible red dot options for the Glock 43X MOS?

Direct-fit red dots for the Glock 43X MOS need to match the RMSc footprint. The SIG Sauer Romeo Zero, Swampfox Sentinel, Holosun EPS Carry, and Shield RMSc all fit right on the slide without adapters. The list is a bit limited—if the footprint doesn’t match, it won’t fit directly.

More info on compatible options is at Reddots Mag's best red dots for Glock 43X MOS.

Can you mount a Holosun optic directly onto a Glock 43X MOS without an adapter plate?

Some Holosun optics, like the Holosun EPS Carry, mount directly if they have the RMSc footprint. Others, such as the Holosun 507K-X2, usually need a thin adapter plate or slide modification because their mounting pattern is a bit different. Always double-check before buying a Holosun for your 43X MOS.

For details, see compatible Holosun options.

Which Trijicon red dot models are best suited for the Glock 43X MOS?

The Trijicon RMRcc is the go-to for the Glock 43X MOS. It doesn’t use the RMSc footprint natively, so you’ll need an adapter plate. Once it’s mounted, you get great durability, clear glass, and several brightness settings.

Read more about the RMRcc setup at best red dots for Glock 43X MOS.

What are the top-rated red dot sights recommended for a Glock 43?

Popular picks for the Glock 43 and 43X MOS include the Holosun 507K-X2, Swampfox Sentinel, SIG Sauer Romeo Zero, and Shield RMSc. Each offers reliable performance and a slim profile for concealed carry. The Holosun EPS Carry gets a lot of love for its enclosed emitter and easy battery changes.

See more recommendations at Outdoormoran's best red dots for Glock 43x MOS.

How do you attach a red dot sight and a light to a Glock 43X MOS?

Mount a red dot sight directly to the optics-ready slide using screws and, if needed, an adapter plate that matches the red dot's footprint. For a light, you’ll need a rail adapter since the standard Glock 43X MOS doesn’t come with one. Once that’s on, you can add a compact pistol light.

Find mounting tips at TheGunZone's red dot fit guide.

Are there any specific red dot mount considerations for the Glock 43?

If you’re thinking about mounting a red dot on your Glock 43 or 43X MOS, the main thing to watch is the optic footprint. Slides cut for the RMSc footprint only fit compatible models—adapters won’t help much here. And don’t forget about screw length. Picking the right size keeps you from chewing up internal parts or ending up with a loose sight. It’s surprisingly easy to overlook, honestly.

There's some extra advice floating around in this Glock Talk red dot thread, if you want to dive deeper.