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GLx RS-15 Spotlight: Key Features and FAQs Answered

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In early 2024, Primary Arms Optics released the GLx® RS-15 Mini Reflex Sight—a high-quality optic specifically designed for competition but adaptable for personal defense and recreation. With its focus on precision and usability, this sight has quickly piqued interest among firearm enthusiasts seeking a versatile and dependable optic for their pistol setup.

Over the last few months, we’ve received a lot of inquiries about the optic, and so today, we’re taking a look at some of the most frequently asked questions about the RS-15 and its unique features! Whether you’re a competitive shooter looking for faster target acquisition or simply interested in improving your pistol’s accuracy, this guide will help you understand if the RS-15 is the right choice for your needs.

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Why Choose the GLx RS-15?

These days, there are many great choices when it comes to pistol reflex sights. We designed the GLx RS-15 to focus on competition-ready performance without compromising on practical durability.

Compared to other optics, the GLx RS-15 offers several compelling advantages for both competitive shooters and those seeking a reliable optic for personal defense or recreational use:

1. Window/Aperture Size

The GLx RS-15 boasts a large window with a 26x20mm aperture, providing superior target acquisition and engagement capabilities. This expansive view allows shooters to maintain situational awareness while focusing on their target, an essential feature for both rapid competitive shooting and effective self-defense.

2. Top Loaded Battery

The RS-15 features a top-loading CR2032 battery compartment, which is a significant advantage for maintaining zero. This design allows for battery changes without removing the optic from the firearm, preserving alignment and saving time on re-zeroing.

3. Proven Reliability

Constructed from 7075 aluminum with a hardcoat anodized finish, the RS-15 is designed to withstand harsh environments and rigorous use. It is waterproof and shockproof with fully potted electronics, ensuring reliable performance under adverse weather conditions and heavy recoil.

4. Lifetime Warranty

We back the GLx RS-15 with a comprehensive lifetime warranty, which reflects our confidence in the durability and quality of the product. It also provides buyers with assurance that their investment is protected against defects and failures, adding an extra layer of value to the optic​.

5. The ACSS Vulcan Reticle

This is our first in-house designed pistol optic to feature the ACSS® Vulcan® Dot reticle. For many, this reticle is reason enough to favor the RS-15 over competitor models, especially when you combine its advantages with the other fast-acquisition features built into the RS-15’s design. Of course, if you prefer a traditional dot alone, there is an GLx RS-15 with 3 MOA Dot Reticle as well, though we highly recommend the ACSS variant, which can already be set on a ‘Dot Only’ mode if desired.

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What is the ACSS Vulcan Dot Reticle?

The ACSS Vulcan Dot reticle is a patented technology that completely innovates the way you aim with a pistol optic. The ACSS Vulcan Dot has two main components: a 3 MOA center aiming dot and a 230 MOA outer circle.

When aiming centered at the target, the user will only see the 3 MOA center dot, as the outer circle is so large that it falls outside the visible window.

However, when the user’s aim is slightly off, the edges of the circle come into view, giving you a built-in correction tool that eliminates the issue of needing to ‘search’ for an aiming point.

The ACSS Vulcan is the only reticle on the market with elements designed not to be seen when aiming properly. However, this corrective circle gives it a unique advantage when correcting your aim and acquiring your reticle in high-speed, dynamic shooting scenarios. Whereas a traditional optic would require you to fall back to iron sights or blindly search for a reticle, the ACSS Vulcan gives you the correction built-into the reticle.

For competition, this could be a major time-saver when shooting off-hand or around difficult barriers. For personal defense, it adds an extra layer of confidence that you can get on-target when overcoming adrenaline, rapid movement, or injury.

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Is the GLx RS-15 Rugged?

The RS-15 is indeed designed to be rugged, making it suitable for various demanding conditions, whether in competitive shooting, tactical applications, or recreational use. This durability is crucial for a sight intended for versatile deployment across different environments.

A key aspect of the RS-15’s ruggedness is its construction from 7075 aluminum, known for its high strength and resistance to wear and tear. This material choice ensures the sight can handle the physical stresses of rapid movements, impacts, and harsh weather conditions without falling short. The sight is also waterproof and shockproof, enhancing its reliability in adverse weather conditions and mud, which are especially common here in Houston.

Another important aspect of the RS-15’s reliability is its electronics. All of the electronics within the RS-15 are fully potted, meaning that they are encased in a protective compound that shields them from moisture, dust, and mechanical stress. Potting is particularly valuable in pistol optics as it ensures that the electronic parts maintain functionality amidst the vibrations and shocks that come with the violent movements of a pistol slide.

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Why does the GLx RS-15 have a C-More Footprint?

The RS-15 uses the C-More mounting footprint because it’s a tried-and-true standard in the competitive shooting scene. C-More systems have been around for a long time and are commonly used in competition pistols. This makes it easy for competition shooters who are already using these setups to upgrade or add the RS-15 to their gear without hassle.

Choosing this footprint also comes down to practical design choices. For instance, the RS-15 features a top-loaded battery, which is convenient for competition shooters because it means you can swap batteries without having to remove the sight or mess with your zero. The footprint used by Holosun 507, for example, doesn’t support this top-loaded design due to its screw pattern—it would interfere with the battery slot.

The newer Trijicon RMR HD gets around this by offsetting the lens, but on some pistols, this would cause the lens to overhang the barrel hood. Thus, we decided to stick with a layout that avoids these potential complications, keeping things straightforward and focused on what competition shooters need most.

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What’s the GLx RS-15’s Battery Life?

The battery life of the Primary Arms Optics GLx RS-15 Mini Reflex Sight is robust, designed to ensure that you won’t frequently be changing batteries, especially when you’re using the features optimally.

Practically speaking, the RS-15 can offer about a year’s worth of battery life on a medium brightness setting if you’re using the optic’s AutoLive® technology. This feature helps conserve battery by automatically turning off the reticle when the optic is not in motion and reactivating it when movement is detected.

The battery duration can also vary depending on how you use the sight and the environmental conditions in which it operates. For instance, colder weather can generally reduce battery life. This makes it hard to give the exact number of hours you can expect, since our testing here in coastal Texas will deliver different results than the Colorado Rockies.

Regardless, if you’re using the ACSS Vulcan Dot variant of the optic, there’s a handy tip to extend the runtime even further: you can disable the Vulcan’s large outer circle when the sight is not in active use, particularly during long storage periods. This reduces power consumption, as the simpler dot-only mode requires less energy.

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What are the RS-15’s Controls?

Speaking of controls, there are a few things to know about the control scheme of the RS-15.

The RS-15 is controlled by two buttons on the left side of the optic: one labeled up, and one labeled down. As you might expect, the up arrow increases brightness, while the down arrow decreases it. At the high end, the optic is bright enough to stand out in broad daylight, while the very lowest settings are reserved for use with night vision devices.

All models of RS-15 can be shut off by holding the UP button for three seconds. On ACSS Vulcan models, holding the DOWN button for three seconds will switch the outer circle on and off.

The relatively small size of the buttons is again due to the optic’s primary role as a high-speed competition reflex. This size gave the best balance of accessibility while ensuring that the buttons wouldn’t ever be pressed on accident, as any accidental press could (in theory) turn off the reticle without the user knowing.

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In conclusion, the Primary Arms Optics GLx RS-15 Mini Reflex Sight is a well-rounded optic that can fit a range of needs.

Its ACSS Vulcan Dot reticle is particularly handy for competitive shooting or personal defense, helping you zero in on targets quickly while providing a level of flexibility to accommodate different scenarios. The decision to use the C-More mounting footprint ensures that it’s compatible with various competition pistols right out of the box, and the top-loaded battery feature makes swapping out cells a breeze.

If you’d like to learn more about reflex sights (such as the RS-15, among others), we have a great introductory guide [Pistol Sights 101] that covers all their benefits. We also have a helpful guide to aiming and applying reflex techniques to get the most out of your new optic once you install it [How to Aim with a Pistol Red Dot Sight].