Best Adapter Plate for Glock 43X MOS: Your Essential Guide
Choosing the right adapter plate for your Glock 43X MOS unlocks its full potential for red dot sights. This guide simplifies the process, helping you find the perfect fit for improved accuracy and a better shooting experience.
So, you’ve got a Glock 43X MOS, and you’re ready to install that sweet red dot sight to make your shots land exactly where you aim. That’s a fantastic upgrade! But then you hit a snag: your new optic doesn’t quite match the mounting holes on your slide. This is where an adapter plate, sometimes called a red dot mount or optic plate, comes in. It’s like a little bridge that connects your pistol to your sight. Picking the wrong one can lead to frustration, and worse, a sight that isn’t secure. Don’t worry, though! We’re going to break down exactly what you need to know, step-by-step, to find the best adapter plate for your Glock 43X MOS. We’ll cover what makes a good plate, what to look out for, and some top choices to get you sighted in quickly and confidently.
Why You Might Need an Adapter Plate for Your Glock 43X MOS
The Glock 43X MOS (Modular Optic System) is a great pistol, designed to accept various red dot sights. However, the “MOS” system uses a specific footprint, which is essentially the pattern of screw holes on the slide. Many popular red dot sights use different mounting systems. Think of it like trying to plug a European appliance into an American outlet – you need an adapter! The adapter plate bridges the gap, ensuring your red dot sight sits flush, securely, and precisely on your Glock 43X MOS slide.
Without the correct adapter, you might find yourself with a wobbly sight, holes that don’t line up, or worse, the inability to mount your optic at all. Getting the right plate means your sight will have a stable platform, which is crucial for consistent accuracy. This isn’t just about making your gun look cool; it’s about making it perform better.
Understanding Optic Footprints: The Key to Compatibility
This is where things can get a little technical, but don’t let it scare you! An “optic footprint” refers to the specific pattern of screw holes on the base of a red dot sight, or on the mounting surface of a firearm. Different manufacturers and even different models within a manufacturer’s line can have unique footprints. Your Glock 43X MOS comes with a set of plates from the factory, but these might not match the footprint of your desired optic. You’ll see terms like:
- RMR Footprint: Popularized by Trijicon’s RMR, this is one of the most common footprints. Many other manufacturers make sights compatible with this pattern.
- DeltaPoint Pro (DPP) Footprint: Used by Leupold’s DeltaPoint Pro and some other optics.
- Doctor Footprint: An older but still used footprint, often seen on Crimson Trace and EOTech sights.
Your Glock 43X MOS might be compatible with certain factory plates (often referred to by numbers like Plate #1, #2, etc.), but if your optic doesn’t match one of those, an aftermarket adapter plate is your solution. You need to know both the footprint of your optic and which optic footprints the adapter plate you’re considering will cover. More on how to find this information is coming up!
What Makes a Good Adapter Plate? Essential Features
Not all adapter plates are created equal. When you’re looking for the best adapter plate for your Glock 43X MOS, keep an eye out for these crucial features:
- Material Strength: A good plate should be made from a durable material that can withstand recoil and the elements. Machined aluminum or steel are excellent choices. Avoid flimsy polymer if you’re serious about durability.
- Precision Machining: The plate needs to be made with tight tolerances. This ensures a snug fit between the plate, the slide, and the optic, preventing movement and maintaining zero.
- Secure Locking Mechanism: How does the plate attach to your slide? Look for plates that use robust screws and, ideally, some form of thread locker or a system that prevents screws from backing out under recoil.
- Corrosion Resistance: Your pistol might be exposed to sweat, rain, or other moisture. A good adapter plate will have a protective coating (like Cerakote or anodizing) to prevent rust and corrosion.
- Proper Fitment: It should integrate seamlessly with the Glock 43X MOS slide. It shouldn’t wobble, protrude excessively, or interfere with your sight picture or firearm function.
- Consider Height: Some plates might add a slight rise, which can affect your ability to co-witness with iron sights. Some are designed to maintain a low profile.
How to Find the Right Adapter Plate: A Step-by-Step Plan
Finding the best adapter plate for your Glock 43X MOS doesn’t have to be a headache. Just follow these simple steps:
Step 1: Identify Your Optic’s Footprint
This is the most critical first step. Look at the product page for your red dot sight online, or check the manufacturer’s website. It will explicitly state the optic’s footprint. Common examples are:
- Trijicon RMR
- Leupold DeltaPoint Pro (DPP)
- Docter
- Holosun K Series (often uses an RMR footprint with slight variations or specific screws, so always double-check)
If you’re unsure, search for your specific red dot model and “footprint” online. You might find forums or product reviews that clarify it.
Step 2: Check Your Glock 43X MOS Factory Plates (Optional but Recommended)
Your Glock 43X MOS likely came with a set of plastic adapter plates. While not ideal for long-term durability or the best fit for all optics, they are designed to mount certain popular sights. Refer to your Glock manual or the Glock official website to see which factory plates correspond to which optic footprints. If your optic’s footprint matches one of these, you could use the factory plate as a temporary solution or to decide if you truly need an aftermarket one. However, for reliability and performance, an aftermarket plate is often superior.
Step 3: Search for Adapter Plates Specifically for Glock 43X MOS that Match Your Optic Footprint
Now, you’ll start searching for plates. Use search terms like:
- “Glock 43X MOS RMR plate”
- “Glock 43X MOS DeltaPoint Pro adapter”
- “Best Glock 43X MOS optic mount”
When you find a plate, read the product description very carefully. It should clearly state which optic footprints it is designed to accept. For example, a listing might say: “Adapter Plate for Glock 43X MOS – Fits Trijicon RMR and Holosun 507C.”
Step 4: Consider Material and Brand Reputation
As mentioned earlier, look for plates made from durable, precision-machined materials like T6 aluminum or steel. Stick with reputable brands known for quality firearm accessories. Companies like Agency Arms, Forward Control Design, C&H Precision, and Calculated Kinetics are well-regarded. Read reviews to see what other users say about durability and fit.
Step 5: Check for Additional Features
Some plates offer advanced features:
- Built-in Rear Sights: Some plates have integrated rear sights, which can be a great backup in case your red dot fails.
- Ambidextrous Design: While less critical for an adapter plate itself, ensure it doesn’t interfere with your pistol’s controls.
- Low Profile Design: Some users prefer a plate that keeps the optic as low as possible to the bore axis.
Top Adapter Plate Options for Glock 43X MOS (Popular Footprints)
Here are some highly-regarded options and types of adapter plates you might find for your Glock 43X MOS, depending on your optic’s footprint. Remember to always verify compatibility with your specific optic model and the plate manufacturer’s specifications.
For RMR-Footprint Optics (Trijicon RMR, Holosun 407C/507C/508T, etc.)
This is by far the most common requirement. Many manufacturers offer plates for this footprint.
Example Table: Popular RMR Footprint Adapter Plates
| Manufacturer | Material | Key Features | Notes |
|---|---|---|---|
| C&H Precision Optics (CHPW) | Machined Aluminum | Very low profile, excellent fit, often includes mounting hardware. | Highly recommended; designed for a precise fit. |
| Agency Arms | Aluminum or Steel | Durable, often part of a larger slide package, but plates sold separately. | Premium option, known for robust construction. |
| Forward Control Design (FCD) | Machined Aluminum | Designed for extreme durability and a secure lockup. | Favored by many for their rugged nature. |
For DeltaPoint Pro (DPP) Footprint Optics (Leupold DPP, etc.)
If you’re running a Leupold DeltaPoint Pro or a compatible optic, you’ll need a plate specifically for this footprint.
Example Table: DPP Footprint Adapter Plates
| Manufacturer | Material | Key Features | Notes |
|---|---|---|---|
| Spiritus Systems | Machined Aluminum | Often provides a very secure and stable mount for DPP optics. | Check availability as product lines can change. |
| RE Factor Tactical (REFT) | Machined Aluminum | Designed for a precise fit and robust performance. | Another solid contender in the aftermarket plate market. |
For Docter Footprint Optics (Various manufacturers)
While less common for newer pistol optics, you might still encounter Docter-footprint sights.
Example Table: Docter Footprint Adapter Plates
| Manufacturer | Material | Key Features | Notes |
|---|---|---|---|
| Von’s Ingenuity (V-I) | Machined Aluminum | Specializes in custom and niche mounting solutions, potentially including Docter. | May require more targeted searching. |
| Various smaller manufacturers | Machined Aluminum | Dedicated plates for specific Docter-mounted guns. | Look for product descriptions that explicitly mention Docter compatibility for Glock MOS. |
Important Note: The firearm industry moves fast! Always double-check current product listings from manufacturers and reputable retailers like Brownells, OpticsPlanet, or direct from the adapter plate makers for the most up-to-date options and verified compatibility.
Installation: What You’ll Need and How to Do It Safely
Installing an adapter plate is usually straightforward, but it requires careful attention. Safety first, then precision!
Tools You’ll Likely Need:
- Your Glock 43X MOS
- Your chosen adapter plate
- Your red dot sight
- Appropriate screwdrivers (often Torx bits, specific sizes like T10, T15, or T20) – check what your plate and optic require.
- Torque wrench (essential for proper torque values to avoid stripping screws or damaging the optic/plate) – a small, low-range torque wrench is best.
- Threadlocker (like Loctite Blue 242 or Vibra-Tite VC-3) – use sparingly.
- A clean, well-lit workspace.
- A cleaning cloth and isopropyl alcohol to degrease surfaces.
Installation Steps:
ALWAYS UNLOAD YOUR FIREARM AND REMOVE ALL AMMUNITION FROM YOUR WORKSPACE BEFORE STARTING ANY MAINTENANCE OR INSTALLATION. VERIFY THE CHAMBER IS EMPTY.
- Remove the Slide: Perform a standard field strip of your Glock 43X MOS. Remove the slide from the frame.
- Remove Factory Plate/Optic: If your MOS slide already has a factory plate or an optic mounted, carefully remove the screws holding it in place. Remove the plate or optic.
- Clean the Slide Deck: Thoroughly clean the mounting area on the slide. Remove any old threadlocker, debris, or oil. A clean surface ensures the plate sits flush and properly. Use isopropyl alcohol on a cloth.
- Prepare the Adapter Plate: Install the adapter plate onto the slide. Some plates use screws that go through the slide from the bottom, while others might use smaller screws to attach the plate to the slide first. Follow your plate’s specific instructions.
- Apply Threadlocker (Optional but Recommended): If your optic’s screws will thread directly into the adapter plate, apply a tiny drop of blue threadlocker to the optic mounting screws. Too much can squeeze out and make removal impossible later, or damage the optic. Let it cure according to the threadlocker’s instructions if specified.
- Mount the Red Dot Sight: Carefully place your red dot sight onto the adapter plate, aligning the mounting holes.
- Install Optic Screws: Insert the optic’s mounting screws through the optic and into the adapter plate (or through the plate into the optic, depending on design).
- Torque Screws Correctly: This is crucial. Use your torque wrench to tighten the optic screws to the manufacturer’s recommended torque specification. DO NOT OVER-TIGHTEN! Over-tightening can strip the threads, crack the optic housing, or deform the plate. Consult your optic’s manual for the exact torque value (often just a few inch-pounds).
- Test Fit and Function: Reassemble your Glock 43X MOS. Cycle the slide a few times. Ensure the optic is secure, doesn’t wiggle, and doesn’t interfere with the slide’s operation.
- Test Fire: Safely go to a range and test fire your pistol. Check if the red dot sight holds zero.
For detailed guidance on proper torque settings, refer to resources like Brownells’ gunsmithing tools section or the specific manuals for your optic and adapter plate.
Troubleshooting Common Issues
Even with the best plate, you might hit a snag. Here are some common problems and solutions:
- Wobbly Optic:
- Cause: Loose screws, incorrect threadlocker, or a poorly machined plate/optic.
- Solution: Re-torque screws to spec. If using Loctite, ensure surfaces are clean. Consider a different plate if it seems ill-fitting.
- Optic Not Holding Zero:
- Cause: Movement due to recoil, improper installation, or a faulty optic.
- Solution: Ensure screws are torqued correctly with threadlocker. Check that the plate is firmly seated on the slide. Try a different optic if the problem persists.
- Screws Won’t Thread In Properly:
- Cause: Misalignment, damaged threads, or using the wrong screws.
- Solution: Gently try to realign the optic and plate. Ensure you have the correct screws for your optic and plate combination. Never force them.
- Plate Doesn’t Fit Slide Perfectly:
- Cause: Incorrect plate for the Glock 43X MOS or a manufacturing defect.
- Solution: Double-check you purchased the correct model plate. Contact the manufacturer or retailer for a replacement if it’s defective.
FAQ: Your Adapter Plate Questions Answered
Q1: Do I really need an adapter plate for my Glock 43X MOS?
Maybe! Your Glock 43X MOS is designed to accept various red dot sights. However, most popular red dots don’t have the exact same screw pattern (footprint) as the Glock MOS system. An adapter plate bridges this difference, ensuring a secure and proper fit. Check if your optic’s footprint matches a Glock MOS factory plate; if not, you’ll need an aftermarket one.