The Glock 20 Gen 4 is a powerhouse pistol chambered in 10mm Auto—an ideal choice for backcountry defense, hunting, and serious range work. Its robust frame, increased slide mass, and high recoil tolerance make it a favorite among shooters who demand raw power. But to fully unlock the potential of this beast, a high-quality red dot sight is a game-changer.
Adding a red dot to your Glock 20 Gen 4 significantly enhances target acquisition speed, precision, and shooting confidence, especially under high-stress conditions like bear defense or competitive shooting. Whether you’re using the MOS version or planning a custom slide cut, there are a variety of optics that fit the Glock 20 platform perfectly—ranging from rugged military-grade models to compact, budget-friendly sights designed for pistol recoil.
In this guide, we’ll explore the best red dot sights for the Glock 20 Gen 4, including models that mount directly to the MOS slide and those requiring an adapter plate. Each optic is chosen for its durability, battery life, clarity, and real-world performance—so you can focus on your target with confidence, no matter what you’re up against.
6 Best Red Dots for Glock 20 Gen 4
1.Holosun SCS-MOS Green Multi-Reticle Dot
If you’re running a full-size Glock MOS pistol and want a red dot that’s reliable, rugged, and completely self-sustaining, the Holosun SCS-MOS Green Multi-Reticle Dot is an excellent choice. Designed to mount directly to Glock MOS slides without an adapter plate, this advanced optic offers a combination of solar-powered innovation, cutting-edge reticle versatility, and durable construction—all tailored for performance under pressure.
The Glock 20 Gen 4, known for its powerful 10mm Auto chambering, demands an optic that can keep up with its recoil and deliver consistent accuracy in demanding environments. That’s where the SCS-MOS stands out. Holosun designed this optic with practicality and resilience in mind, especially for shooters who rely on their pistol for backcountry defense, law enforcement, or tactical performance. Unlike many red dots that rely solely on battery life or require adapter plates to fit Glock slides, the SCS-MOS integrates seamlessly into the factory MOS cut, offering a lower profile and more intuitive co-witnessing with standard-height sights.
Additionally, the green reticle is easier to pick up for many users—especially in daylight—making it a top choice for fast target acquisition under stress. Whether you’re navigating deep woods, defending against predators, or honing your marksmanship at the range, the SCS-MOS delivers clarity, reliability, and low-maintenance operation that few optics in its class can match.
Product Features
1.Solar Charging System
The standout feature of the Holosun SCS-MOS is its self-sustaining power source. It’s equipped with a solar charging system and internal rechargeable battery rated for 20,000 hours of use. Thanks to its multi-directional light sensors, the optic automatically adjusts brightness based on ambient lighting, eliminating the need for manual adjustments in dynamic environments. For added control, it also includes a 30-minute brightness override mode and a low-power warning indicator to let you know when a charge is needed days in advance.
2.Multi-Reticle System (MRS)
This sight features Holosun’s MRS technology, giving you three reticle choices:
- 2 MOA dot only for precision shooting
- 32 MOA circle only for rapid acquisition
- Circle + dot combination for quick transitions and holdover guidance
This allows you to tailor your sight picture based on the environment and shooting distance, making the SCS-MOS one of the most versatile optics on the market.
3.Titanium Housing & Premium Optics
Built with a titanium housing, the SCS-MOS is both lightweight and incredibly durable—ideal for a powerful handgun like the Glock 20. The optical glass is multi-coated for glare reduction, improved light transmission, and minimized power consumption. These coatings also enhance reticle brightness and clarity under all lighting conditions, while maintaining excellent resistance to wear and tear.
Key Specifications
- Reticle: Green 2 MOA Dot & 32 MOA Circle (Selectable)
- Magnification: 1x (Parallax-free, Unlimited Eye Relief)
- Power Source: Solar & Internal Rechargeable Battery
- Battery Life: Virtually Unlimited
- Brightness Control: Auto, with manual override
- Housing Material: Titanium
- Window Size: 0.58″ x 0.77″
- Adjustment per Click: 1 MOA
- W&E Travel Range: ±30 MOA
- Light Wavelength: 540nm
Pros
- No adapter plate needed for Glock full-size MOS models
- Solar-powered with rechargeable battery – potentially unlimited battery life
- MRS reticle system gives you three sight options in one optic
- Titanium body offers excellent strength-to-weight ratio
- Clear, multilayer-coated glass for a crisp, distortion-free sight picture
- Auto-brightness + manual override ensures optimal reticle visibility in all lighting conditions
Cons
- No permanent manual brightness control – override mode is temporary only
2.ADE RD3-013 Reflex Red Dot
The ADE RD3-013 is a compact, durable, and feature-packed reflex sight that debuted at the 2019 SHOT Show, delivering dependable performance in a budget-friendly package. Designed with both entry-level and experienced shooters in mind, this red dot sight is ideal for Glock MOS pistols and a wide variety of other handgun platforms. Whether you’re using your pistol for home defense, range time, or tactical carry, the RD3-013 offers a dependable aiming solution without unnecessary complexity.
One of the biggest highlights of this optic is its advanced battery technology, offering up to 2,000 hours on the brightest setting and up to 30,000 hours on the lowest using a CR1632 battery (included). Unlike many red dots in this price range, the RD3-013 includes a picatinny rail mount for rifles or carbines out of the box, with optional handgun-specific plates sold separately.
Built for users who prefer manual control, this optic stays on until you power it off. It also remembers your last brightness setting, so you don’t need to reset it every time. With a 4 MOA dot, a shockproof and waterproof housing, and compatibility with several major handgun brands, the RD3-013 punches well above its weight.
Product Features
1. Advanced Battery Performance
The RD3-013 uses an efficient CR1632 battery to deliver impressive runtime—up to 2,000 hours on high and 30,000 hours on the lowest setting. This means less downtime and fewer battery swaps for the user.
2. Manual Operation with Brightness Memory
This optic features a single-button control system. Hold the UP arrow to power on, hold for 3 seconds to turn off, and tap to adjust brightness. Best of all, the optic remembers your last brightness level, ensuring you’re always ready without readjusting.
3. Versatile Mounting Options
The RD3-013 fits directly onto Glock MOS Gen4 and Gen5 models (17, 19, 34, 35, 40, 41). It also works with ADE’s handgun mounts for Beretta, HK USP, SIG P226, Springfield, Ruger, and more. A picatinny mount is included, and handgun-specific plates can be purchased separately to suit your platform.
4. Rugged, Weather-Resistant Build
Built to survive real-world use, the RD3-013 is shockproof, fogproof, and waterproof (rated for 30 minutes under 4 feet of water). Its compact body measures 1.75″ x 1.25″ x 1.15″, making it suitable for both compact and full-size pistols.
Key Specifications
- Reticle Size: 4 MOA Red Dot
- Brightness Levels: Multiple (Manual Adjustment)
- Auto Shut-Off: No (Manual Only)
- Battery Type: CR1632 (Included)
- Battery Life: Up to 30,000 hrs (Low), 2,000 hrs (Bright)
- Mounting Footprint: Doctor/Vortex Venom
- Included Mount: Picatinny Rail
- Additional Mounts: Sold separately for pistols
- Dimensions: 1.75″ L x 1.25″ W x 1.15″ H
- Construction: Shockproof, Fogproof, Waterproof (4ft for 30 minutes)
- Adjustment Clicks: 1 MOA (Windage & Elevation with Audible Clicks)
- Night Vision Setting: Yes (Lowest level not visible to naked eye)
Pros
- Long battery life with included CR1632 battery
- Manual brightness control with memory function
- Compatible with Glock MOS Gen4/Gen5 and multiple handgun platforms
- Picatinny mount included
- Affordable and easy to install
- Shockproof and waterproof construction
- Night vision-compatible low brightness setting
Cons
- No auto shut-off (can drain battery if left on)
3.ADE RD3-012 Reflex Red Dot
The ADE RD3-012 Delta is a smartly upgraded reflex red dot sight designed for shooters who demand reliability, ease of use, and affordability in a rugged optic. As an enhanced version of previous ADE models like the RD3-006 and RD3-009, the Delta incorporates Motion Awake technology, self-locking windage/elevation adjustments, and a top-loading battery design—making it a standout in its category for both handgun and rifle users.
Ideal for pistol platforms that accept the Doctor/Vortex Venom/Burris Fastfire footprint, the RD3-012 offers a clean, low-profile design without the rear locking screws found in older generations. This streamlined profile makes it better suited for rapid deployment and holster compatibility, especially for EDC and tactical use. Whether you’re upgrading your Glock MOS, Canik TP9, or other optics-ready pistols (with compatible plates), the RD3-012 Delta brings a lot of value in a small package.
Product Features
1. Motion Awake Technology
One of the most user-friendly upgrades, the Delta enters sleep mode after 5 minutes of inactivity, preserving battery life. As soon as motion or vibration is detected, it automatically wakes up and returns to the last brightness setting—a feature typically seen in much more expensive optics.
2. Top-Load Battery System
Forget about removing your optic every time the battery dies. The RD3-012 uses a top-loading CR1632 battery, so replacements are quick and easy without the need to re-zero the sight.
3. Self-Locking Adjustments
The elevation and windage turrets now feature a self-locking design, eliminating the need for external locking screws. This makes precision zeroing faster and more secure, with less chance of drift during extended use.
4. User-Friendly Controls
- Hold DOWN for 3 seconds to power on/off
- Hold UP for 3 seconds to change reticle pattern
- Tap UP or DOWN for quick brightness adjustments
This simple two-button setup makes the sight intuitive for both beginners and experienced shooters.
5. Wide Compatibility
The RD3-012 fits most optic-ready pistols or mounts that use the Doctor/Venom/Burris Fastfire footprint. It is not compatible with RMR or RMS/RMSC footprints, so users should double-check their handgun’s mounting system before purchase.
Key Specifications
- Model Name: ADE RD3-012 Delta
- Reticle Type: Red dot with selectable pattern
- Mounting Footprint: Doctor / Vortex Venom / Burris Fastfire
- Battery Type: CR1632 (Top-loading)
- Auto Sleep/Wake: Yes (after 5 mins of inactivity)
- Brightness Adjustment: Manual (Up/Down buttons)
- Waterproof / Shockproof / Fog-Resistant: Yes
- Adjustment Clicks: Self-locking 1 MOA windage/elevation
- Parallax: Minimal, with precision-ground optics
- Included in Box: Red dot, Picatinny mount (removable), screws, lens cloth, tool, protective cover, manual
Pros
- Motion Awake feature conserves battery and ensures readiness
- Top-loading battery is convenient—no re-zeroing after changes
- Compatible with a wide range of handguns and mounts
- Self-locking turrets improve zero retention
- Compact, streamlined design for better holster compatibility
- Multiple brightness levels and selectable reticle mode
Cons
- No solar backup (battery-powered only)
4.ADE RD3-009 Reflex Red Dot
The ADE RD3-009 Crusader is a rugged, compact reflex sight built for shooters seeking reliability, affordability, and fast target acquisition. First released in 2014, this optic has received significant upgrades over the years—offering improved durability, enhanced zero retention, and a more refined optical experience. Designed in Oregon, the RD3-009 now incorporates modern tech like Motion Awake, making it a reliable companion for tactical, competition, or concealed carry use.
Its compatibility with a wide range of optics-ready pistols and mounting plates using the Vortex Venom / Burris Fastfire footprint means it fits popular platforms like Glock MOS, Springfield OSP, and any handgun with matching rear sight dovetail mounts. Whether you’re upgrading your pistol setup or adding a red dot to your rifle via the included Picatinny base, the RD3-009 is an excellent blend of value and function.
Product Features
1. Upgraded Design for 2024 and Beyond
The RD3-009 has been redesigned with reinforced internals and improved construction, specifically engineered to withstand harsh recoil and maintain zero under demanding use. These enhancements make it a far more durable optic than earlier versions.
2. Motion Awake Battery Technology
Powered by a CR2032 lithium battery (included), this sight features Shake Awake Technology, which puts the optic to sleep during periods of inactivity and instantly wakes it up when movement is detected. This ensures that the optic is always ready when you need it while also conserving battery life.
3. Flexible Mounting Options
The RD3-009 ships with a Picatinny mount, making it ready for rifles, PCCs, or shotguns. For handgun use, it’s compatible with mounting plates that replace rear dovetail sights or optic-ready pistols with cuts for Vortex Venom / Burris Fastfire footprints—like Glock MOS and Springfield OSP models.
4. Precision Windage & Elevation Adjustments
With fully adjustable and lockable windage and elevation, the RD3-009 offers 1 MOA click adjustments to zero in with accuracy. Unlimited eye relief and a 5 MOA dot give fast target acquisition and intuitive aiming under pressure.
5. Built for Harsh Conditions
The optic is shockproof, waterproof, and fog-resistant, with precision-ground lenses that are polished for minimal parallax and a clear sight picture. Whether you’re shooting in the rain or at the range, it maintains reliable clarity and function.
Key Specifications
- Model: ADE RD3-009 Crusader
- Dot Size: 5 MOA Red Dot
- Brightness Settings: 5 Manual Illumination Levels
- Battery Type: CR2032 (Included)
- Battery Life: Long-lasting with Motion Awake
- Mounting Footprint: Vortex Venom / Burris Fastfire / Doctor
- Included Mount: Picatinny Base
- Windage/Elevation: 1 MOA Click, Fully Adjustable & Lockable
- Construction: Shockproof, Waterproof, Fog-Resistant
- Parallax: Virtually Eliminated
- Eye Relief: Unlimited
- Reticle Activation: Motion Awake / Shake Awake
Pros
- Upgraded design withstands recoil and holds zero better
- Shake Awake technology extends battery life and ensures readiness
- Picatinny and optics-ready pistol compatibility
- Clear sight picture with minimal parallax
- Easy brightness and reticle adjustment
- Durable and weather-resistant build
Cons
- Professional installation recommended to avoid mounting errors
5.Generic 20 mm RMR-Style 3 MOA Red Dot
For shooters seeking a no-frills, budget-friendly optic that delivers reliable performance, the Generic 20mm RMR-Style 3 MOA Red Dot Sight stands out as an impressive value. With a rugged build, bright reticle, and versatile performance, this optic is an excellent match for handguns, rifles, or shotguns, especially for those new to red dots or looking for an affordable backup sight.
Despite its low cost, this sight doesn’t cut corners on durability or clarity. With a 45mm wide tubeless field of view, multi-coated optics, and six brightness levels, it ensures quick target acquisition from dawn till dusk. Whether you’re hunting or at the range, the 3 MOA red dot provides a precise aiming point that remains stable even after repeated use.
Product Features
1. Strong Construction with Reliable Zero Retention
Built with a forged aluminum housing, this optic can endure rough handling, recoil, and inclement weather. Even after over 200 firing cycles, it consistently holds zero, making it a trustworthy companion for both beginners and seasoned shooters.
2. Full Field of View for Fast Target Acquisition
The tubeless design and 45mm reflector give you a wide, unobstructed view—ideal for tracking moving targets and transitioning between short and medium ranges. This design promotes better situational awareness and quicker engagement, perfect for hunting or tactical scenarios.
3. Day & Night Visibility
Thanks to anti-reflective lens coatings, the red dot remains crisp and visible in any lighting condition—daylight, dusk, or nighttime. This ensures you maintain a clear, sharp sight picture no matter when or where you’re shooting.
4. Multi-Coated Objective Lens
The amber-tinted, scratch-resistant lens enhances contrast and image clarity while resisting wear and tear. The dot intensity and power controls are smartly placed on the left side of the sight for easy access, offering six brightness levels to fine-tune visibility.
5. Quick Installation & All-Weather Performance
Designed for fast and secure installation, this optic works with most RMR-style mounts. It’s ultra-lightweight, shockproof, and waterproof, giving it dependable performance in a variety of shooting environments.
Key Specifications
- Dot Size: 3 MOA Red Dot
- Brightness Settings: 6 levels
- Lens Coating: Multi-coated, amber-tinted
- Mount Compatibility: RMR-style footprint
- Construction: Forged aluminum housing
- Reticle Type: Red dot with auto shut-off
- Field of View: Wide (45mm reflector)
- Weather Resistance: Waterproof & Shockproof
- Power Controls: Side-mounted (left)
Pros
- Budget-friendly yet durable
- Holds zero well even after repeated recoil
- Wide field of view enhances speed and accuracy
- Clear sight picture in all light conditions
- Six brightness levels with easy side control
- Lightweight and easy to install
- Weather-resistant for outdoor use
Cons
- Auto shut-off may not suit every user
6.Trijicon RMR Type 2 (High-End)
The Trijicon RMR Type 2 is the gold standard when it comes to rugged, high-performance micro red dot sights. Designed for military, law enforcement, and serious civilian shooters, this optic is built to withstand the harshest conditions while delivering unmatched precision, durability, and reliability. Whether mounted on a handgun, carbine, or shotgun, the RMR Type 2 delivers professional-grade performance trusted in real-world combat and duty applications.
Backed by military-proven construction, this optic features a forged aluminum housing, adjustable LED brightness settings, and true-color multi-coated lenses for maximum clarity. It also offers automatic brightness adjustment and manual override, making it adaptable in all lighting conditions. From its rugged build to its long battery life and crisp 3.25 MOA dot, every detail of the RMR Type 2 reflects top-tier engineering.
Product Features
1. Battle-Proven Durability
Crafted from military-grade 7075-T6 aluminum, the RMR Type 2 is designed to endure extreme abuse. It’s shockproof, waterproof up to 20 meters, and resists fog, vibration, and harsh recoil. Its patented shape helps redirect impact away from the lens to protect your aiming point.
2. Dual Brightness Control
The sight features both automatic brightness adjustment based on ambient lighting and a manual mode with 8 brightness settings (including 2 night vision-compatible levels). This allows seamless transitions between bright daylight and low-light environments.
3. 3.25 MOA Red Dot Reticle
Ideal for both speed and precision, the 3.25 MOA red dot offers a perfect balance—small enough for accurate shots at distance, yet large enough for fast target acquisition in close quarters.
4. Reliable Battery Life
Powered by a single CR2032 battery, the RMR Type 2 delivers up to 4 years of continuous use at setting 4. Combined with its battery-saving auto-adjust feature, it ensures long-term readiness with minimal maintenance.
5. Versatile Mounting and Compatibility
The RMR Type 2 uses the Trijicon RMR footprint, making it compatible with a wide range of mounting solutions for handguns, rifles, and shotguns. It fits seamlessly on many optics-ready pistols and can be paired with co-witness iron sights for backup aiming.
Key Specifications
- Model: Trijicon RMR Type 2
- Dot Size: 3.25 MOA Red Dot
- Brightness Settings: 8 total (2 NV compatible) + auto adjust
- Battery Type: CR2032
- Battery Life: Approx. 4 years at setting 4
- Housing Material: 7075-T6 forged aluminum
- Mounting Footprint: Trijicon RMR
- Adjustment Clicks: 1 MOA per click (windage & elevation)
- Waterproof: Up to 20 meters (66 ft)
- Weight: Approx. 1.2 oz (without mount)
Pros
- Industry-leading ruggedness and reliability
- Dual brightness modes with night vision compatibility
- Long battery life with auto-adjust feature
- Exceptional optical clarity and light transmission
- Holds zero under heavy recoil
- Trusted by military and law enforcement worldwide
Cons
- Premium price point
Also Read: Best Red Dot for Glock 45 9mm
Factors to consider when choosing Best Red Dots for Glock 20 Gen 4
1. Recoil Resistance
The Glock 20 fires the hard-hitting 10mm Auto round, so your red dot must be shockproof and able to handle high-recoil stress without losing zero. Look for optics with rugged housings made of 7075-T6 aluminum or titanium, and avoid cheaper plastic models.
2. Mounting Compatibility
Ensure your red dot is compatible with the Glock 20 Gen 4 slide:
- If your pistol is MOS, check which adapter plate is needed for your optic’s footprint (e.g., RMR, RMSc, DPP).
- If it’s non-MOS, you’ll need a dovetail mount or have the slide milled for a direct fit.
3. Reticle Size (MOA)
Red dot size impacts speed and precision:
- 2–3 MOA: Best for precision shooting and longer distances.
- 5–6 MOA: Ideal for fast target acquisition in close quarters or defense scenarios.
Choose based on your shooting style—backcountry defense may favor a larger dot for speed, while range or hunting shooters may prefer smaller dots.
4. Battery Life and Power Options
Look for optics with:
- Long battery life (50,000+ hours)
- Auto-off and Shake Awake features to preserve power
- Top-loading batteries for easy replacement without removing the sight
Models like the Holosun 507C or SCS-MOS offer solar backup as well.
5. Durability and Weather Resistance
Opt for red dots that are waterproof, fog-resistant, and built for tough environments. A durable optic ensures reliable performance in the rain, snow, or wilderness.
6. Enclosed vs. Open Emitter
- Open emitters (like RMRs or 507C) are lighter but can get obscured by dirt or water.
- Enclosed emitters (like Holosun 509T or EPS) protect the lens and emitter, making them more reliable in extreme conditions.
FAQS
1. Do I need an MOS model Glock 20 Gen 4 to mount a red dot?
Yes, having the MOS (Modular Optic System) version of the Glock 20 Gen 4 makes mounting a red dot much easier. It comes with a factory-cut slide and adapter plates for popular optic footprints. If your Glock 20 Gen 4 is non-MOS, you’ll need to either get the slide milled or use a rear sight dovetail mounting plate.
2. What red dot footprint fits the Glock 20 Gen 4 MOS?
The Glock MOS platform supports multiple footprints depending on the adapter plate used. The most common compatible red dot footprints are:
- Trijicon RMR
- Holosun 507C/508T
- Leupold Deltapoint Pro
Always ensure you match the optic footprint to the plate installed on your slide.
3. Is a red dot durable enough for the 10mm recoil of the Glock 20?
Yes—but only if you choose a rugged, quality red dot. Models from Holosun, Trijicon, and ADE are known for handling high-recoil calibers like 10mm Auto. Look for features like aluminum or titanium housing, vibration resistance, and shockproof construction to ensure long-term durability.
4. What size MOA dot is best for a Glock 20 red dot sight?
A 3 MOA to 6 MOA dot is ideal for most shooters.
- Smaller dots (2–3 MOA) offer more precision at longer distances.
- Larger dots (6 MOA and up) are better for rapid target acquisition in close-range defense scenarios, such as wilderness protection from predators.
Conclusion
Finding the best red dot for your Glock 20 Gen 4 is about balancing rugged performance, fast target acquisition, and reliable compatibility. Given the 10mm Glock’s powerful recoil and full-size frame, your optic must be built to withstand abuse while offering quick sight picture recovery. Whether you prefer advanced features like shake-awake technology and multiple reticle options, or you’re focused on a rugged, no-nonsense dot that just works, there’s a red dot sight to fit your shooting style and budget.
Options like the Trijicon RMR Type 2 offer military-grade performance, while Holosun SCS-MOS delivers solar charging and multi-reticle flexibility. For those on a budget, sights like the ADE RD3-013 and Generic RMR-style red dots still provide solid value with dependable function. Each option brings something unique to the table—so choose the one that matches your needs, whether for self-defense, hunting, or range shooting.
With the right red dot mounted securely, your Glock 20 Gen 4 becomes faster, more accurate, and more capable in any scenario.