MOS 43X: Complete Guide to Glock's Optics-Ready Slimline Pistol

The Glock 43X MOS is a slim, subcompact 9mm pistol designed specifically for concealed carry with an optics-ready slide. The MOS (Modular Optic System) allows shooters to mount micro red dot sights directly to the slide, making it faster and more accurate for target shooting without needing additional adapter plates for most popular optics. This compact firearm measures 6.50 inches in overall length with a 3.41-inch barrel and maintains a thin 1.10-inch width.

The pistol holds 10 rounds in its flush-fitting magazine and weighs approximately 18.55 ounces when empty. Glock designed the 43X MOS with a black nDLC finish and front-to-back slide serrations for better handling. The polymer frame includes texture for a secure grip and a small rail section for mounting lights or lasers.

Understanding the features and capabilities of the 43X MOS helps shooters decide if this optics-ready pistol fits their concealed carry needs. The combination of slim dimensions, decent capacity, and red dot compatibility makes it a popular choice for everyday carry.

Key Takeaways

• The Glock 43X MOS features an optics-ready slide for mounting red dot sights and holds 10 rounds of 9mm ammunition

• The pistol measures 1.10 inches wide and weighs 18.55 ounces empty, making it suitable for concealed carry

• The MOS version includes a small accessory rail and improved grip texture compared to standard models

Key Features and Design of the MOS 43X

The G43X MOS combines a factory-milled optics-ready slide, refined grip ergonomics with a comfortable beavertail design, and precision manufacturing elements like the Glock Marksman Barrel to deliver a well-rounded concealed carry pistol. These features work together to create a pistol that balances modern upgrades with Glock's proven reliability.

Modular Optic System and Micro-Optics Compatibility

The Modular Optic System represents the most significant upgrade on the G43X MOS. The slide comes factory-milled to accept micro red dot sights using the Shield RMSc footprint.

This cut allows direct mounting of popular micro-optics like the Holosun 507K and Shield RMSc without requiring aftermarket slide milling. The optic mounting dramatically improves target acquisition speed, especially in low-light conditions where iron sights become harder to use.

Shooters should note that Glock does not include the mounting plates with the pistol. Buyers need to purchase the appropriate adapter plate separately and verify compatibility with their chosen optic before installation.

The MOS system also works with suppressor-height sights, which co-witness through most micro red dots to provide a backup aiming solution.

Frame Ergonomics and Compact-Size Grip

The Glock 43X features a slim 1.10-inch-wide frame that makes concealed carry comfortable for extended periods. The single-stack design keeps the pistol profile minimal while maintaining a 10+1 capacity.

The grip includes an integrated beavertail that protects the shooter's hand from slide bite during recoil. This beavertail design also helps position the hand higher on the frame for better recoil control.

Glock added textured grip panels on the frame to improve retention during firing. The compact-size grip provides enough purchase for most hand sizes while remaining easy to conceal.

The short trigger distance accommodates shooters with smaller hands who struggle with full-size pistols. The Glock slim mounting rail on the dustcover accepts compact weapon lights and lasers, though the single-slot design limits accessory options compared to larger Glock models.

Glock Marksman Barrel and Precision-Milled Front Serrations

The Glock Marksman Barrel measures 3.41 inches and features enhanced rifling that improves accuracy over previous Glock barrel designs. This barrel design uses tighter tolerances and improved manufacturing to deliver better precision at typical defensive distances.

The slide includes precision-milled front serrations that provide a gripping surface for press checks and manual slide manipulation. These serrations match the rear serrations to offer consistent purchase points whether the shooter racks the slide from the front or rear.

The nDLC finish on the steel slide provides corrosion resistance and wear protection during daily carry. This finish holds up well against sweat, moisture, and regular holster use without showing excessive wear patterns.

Performance, Carry, and Practical Use

The Glock 43X MOS delivers solid performance in a package designed for daily concealed carry. Its slim profile accommodates standard-capacity magazines while maintaining excellent concealability, and small design features like the reversible magazine catch improve versatility for different shooters.

Concealed Carry Suitability and Everyday Reliability

The 43X MOS measures just 1.10 inches wide, making it one of the slimmest 9mm handguns available for concealed carry. This narrow profile allows the pistol to tuck comfortably inside the waistband without printing through clothing.

At 18.7 ounces unloaded, the lightweight polymer frame reduces fatigue during all-day carry. The grip length provides a full three-finger hold while keeping the overall length at 6.5 inches, which balances control with concealability.

Glock's Safe Action System maintains consistent trigger pull and built-in safety features without adding external levers. The pistol functions reliably in varied weather conditions including rain, heat, and dusty environments. The nDLC finish on the slide resists corrosion from sweat and holster wear during daily carry.

Magazine Capacity, Slim Magazine, and Ammunition Options

The 43X MOS ships with 10-round magazines chambered in 9mm Luger. This capacity exceeds traditional single-stack options while maintaining the slim magazine profile essential for concealment.

Aftermarket options expand capacity significantly. Shield Arms S15 magazines hold 15 rounds while fitting flush with the grip, adding five extra rounds without increasing width. Some users recommend upgrading to a metal magazine catch when using steel magazines to prevent accelerated wear on the factory polymer component.

The 9mm Luger chambering offers wide ammunition availability and manageable recoil in the compact frame. Shooters can choose from defensive hollow points, practice FMJ rounds, and specialty loads depending on their needs.

Reversible Magazine Catch and User Adaptability

The reversible magazine catch allows left-handed and right-handed shooters to configure the pistol for their dominant hand. Switching the catch position takes minutes and requires no special tools or gunsmithing.

This ambidextrous capability makes the 43X MOS suitable for families or training environments where multiple shooters share the same handgun. The magazine release sits in an accessible position without being prone to accidental activation during carry.

Combined with extensive aftermarket support, users can further customize triggers, sights, and grip textures to match individual preferences and hand sizes.

Frequently Asked Questions

The Glock 43X MOS raises common questions about its generation features, package contents, color choices, and practical advantages for carriers. Buyers also want to know about state regulations and how this pistol performs compared to competing firearms.

What improvements does the Glock 43X MOS Gen 5 offer over previous generations?

The Glock 43X MOS belongs to the Gen 5 family and includes several refinements over earlier Glock generations. The pistol features an improved nDLC finish on the slide that offers better durability and corrosion resistance. Front slide serrations provide better grip for press checks and slide manipulation.

The Gen 5 platform removed the finger grooves from the grip frame. This creates a more universal fit for different hand sizes. The magazine well has a flared design that makes reloading faster and easier.

Can you describe the contents of the Glock 43X MOS package and what additional accessories it includes?

The standard Glock 43X MOS package includes the pistol with two 10-round magazines. Buyers receive a speed loader, cleaning kit, and lock for safe storage. The pistol comes in a hard plastic carry case.

The MOS version includes mounting screws for attaching compatible optics. However, the gun does not come with adapter plates included in the package. Shooters need to purchase adapter plates separately based on their chosen red dot sight.

What are the color options available for the Glock 43X MOS, and how do they vary?

The Glock 43X MOS comes with a traditional black nDLC finish on the slide as its standard option. This finish provides a uniform all-black appearance across the entire pistol. The polymer frame is also black, creating a monochromatic look.

Some retailers offer models with different finish options or frame colors. These variations typically come from special editions or distributor exclusives. The standard factory model maintains the all-black configuration.

What advantages does the Glock 43X MOS provide for concealed carry or personal defense?

The pistol's slim profile at 1.10 inches wide makes it easier to conceal under various clothing options. The compact size works well for inside-the-waistband carry positions. At 18.55 ounces with an empty magazine, the weight remains manageable for all-day carry.

The optics-ready slide allows shooters to mount red dot sights for faster target acquisition. This feature can improve accuracy in defensive situations. The 10-round magazine capacity provides a reasonable balance between size and ammunition supply for personal protection.

Are there any legal restrictions to be aware of when purchasing a Glock 43X MOS in certain states?

State and local laws vary regarding handgun purchases and ownership. Some states have restrictions on magazine capacity that could affect the standard 10-round magazines. Buyers must comply with their state's waiting periods, background check requirements, and registration laws.

Certain jurisdictions require additional permits or licenses before purchasing handguns. Some states restrict concealed carry permits based on specific criteria. Potential buyers should check their local and state regulations before purchasing any firearm.

How does the Glock 43X MOS compare to other firearms in terms of performance and reliability?

The Glock 43X MOS is known for its reliability in various conditions. The pistol uses Glock's proven Safe Action trigger system and standard internal components. It handles both standard 9mm ammunition and +P loads effectively.

The pistol competes directly with other single-stack 9mm subcompacts in the market. Its optics-ready design gives it an advantage over models without mounting capabilities. The Glock 43X MOS ranks among the most popular in the subcompact line alongside similar models like the Glock 48.