When it comes to mini reflex red dot sights, everyone seems to have one or more in their catalog. Primary Arms has them also. The difference is that Primary Arms has broken the “same old dot” mold by designing and using an innovative reticle called the ACSS Vulcan. They have put this reticle in their brand new GLx RS-15 mini reflex sight. I tested the GLx RS-15 on a shotgun and a pistol just to see how it worked.

For everyday purposes, the Primary Arms GLx RS-15 is a reflex red dot sight. That is only the beginning of the story. First, the RS-15 is in Primary Arms’ GLx line. The GLx line is Primary Arms’ mid-tier optics line. That means you get a higher class of technology and materials at a fair price. The RS-15 comes in at $359 dollars, which isn’t bad when you count how many features are in it. In this line you tend to get new and innovative reticles and sharper glass, leading to a crisper dot. It also has the ACSS Vulcan reticle. Which I will explain, at length, later. Some of the other features it has include: A top load battery, 7075 aluminum housing, and Autolive technology, just to name a few.

Camera is closer to optic, to give an almost complete view of the reticle

The GLx RS-15’s ACSS Vulcan reticle is an innovative design. For simple explanation, it is essentially a 3 MOA red dot. Then it has an outer ring around that dot. That outer ring is 250 MOA. So what happens is that when you hold the RS-15 at arms length, the outer ring is not seen if the dot is in the center of the window. If you move the sight up/down or left/right, the outer circle starts to come into the window's view. This allows the shooter to see which way the gun needs to move, so you can get back to having the dot centered. Take for instance you see a curved line in the right or left side of the window. Just move the muzzle of the firearm toward the direction of that curved line, and you should then see the aiming dot. Same with up or down. If the curved line is on top, move the muzzle up, if it is toward the bottom of the window, move the muzzle down. The ACSS Vulcan reticle is a great reticle to learn how to shoot red dots on pistols. Yes, it even helps out seasoned shooters like myself. After you use the Vulcan reticle for a while, and want to try just a normal dot sight picture, it has an option to turn off the outer ring so that it is just the 3 MOA dot. Just hold down the brightness down button for 3 seconds and it will cycle between the two modes. I’ve been really impressed with the ACSS Vulcan reticle.

Primary Arms’ Autolive function is also built into the GLx RS-15. However, it works a little differently than their normal Autolive version. After around 10 seconds of no movement, the RS-15 shuts off the 250 MOA ring and leaves just the 3 MOA dot. Then after around 4 minutes of no movement, it shuts down the dot reticle. Have no fears, just barely move the RS-15 and the full Vulcan reticle will come back on. This helps aid in longer battery life. Battery life is pretty good. Primary Arms states 25,000 plus hours on medium setting with just the dot, and around 5,000 hours with the Vulcan reticle. It may sound substantially less, but 5000 hours is still 200 days of continuous “on.” And with the Autolive, it will not be continually on for 200 days. I’m a big fan of Autolive, or any of the auto on/off systems.

Mounting the GLx RS-15 might lead to some hassles. The RS-15 uses a C-More mounting footprint. Trying to find an actual C-More footprint optics cut is not easy. Slides with these optics cuts are available, but not nearly as prevalent as a RMR footprint cut. However, If you have a slide cut for a Delta Point Pro (DPP), and it doesn’t have the recoil lug bosses built in, the RS-15 will mount right up. This is because the screw hole spacing is the same for a DPP or a C-More footprint. This mounting footprint is the GLX RS-15’s biggest flaw. First I mounted the RS-15 up to a shotgun, with the help of a Warne Red-dot Shotgun Rib Reflex Mount. On a side note, the Warne mount is fantastic. It mounts to the shotgun's rib, securely, and has options for just about any red dot footprint imaginable. I then proceeded to put it on a P320 with a Grey Ghost Precision (GGP) slide. I did this because the GGP slide is cut for a DPP and doesn't have any recoil bosses to make the RS-15 not bolt up. That is where it stays. Not because it didn’t work on the shotgun, but because I like it better on the pistol.

Besides the ACSS Vulcan reticle and Autolive functionality, the GLx RS-15 has some other great features. First up is the actual window size, which is 26x20mm’s. The window size is decently large and seemed easy for me to get on target with. Next is the RS-15’s top load CR2032 battery. Which also comes with a combo wrench to make removing the battery cover easy. The 7075 aluminum housing is stronger than comparable sights that use 6061 aluminum. Probably most notable, is that the RS-15 has 0.5 MOA click adjustments. Almost all mini reflex sights use a 1 MOA adjustment, and some do not have clicks. Lastly, the buttons on the right side control brightness. It has 13 brightness settings, 3 of which are night vision compatible. The top brightness settings are super bright.

The GLx RS-15 is one of the clearest red dots I have used. The clarity is just amazing. I say this because with my astigmatism, red dot’s are usually a little starred out for me, making them a little blurry. Not the RS-15. I don’t know what Primary Arms did to get this red dot so clear, but I like it. Maybe it is the very slightly tinted blue lens. Either way, it works. In fact, it is the first time, in a while, that I can turn the brightness all the way up and not have the dot look distorted.

I mentioned running the GLx RS-15 on a shotgun. I wanted to try out a non conventional use for it. I really liked shooting trap with the RS-15. However, the 250 MOA outer ring didn’t really do anything for the shotgun. Something about looking down a long gun barrel that tends to line up the sight. I am not sure if it helped me shoot trap better, but I see how having something like the RS-15 on a field shotgun could be immensely useful. The dot just made aiming at a moving target easier.

After the shotgun try out, I proceeded to go conventional. Using the GLx RS-15 on a handgun is where it really shines. This is where the ACSS Vulcan reticle can be used to its full potential. I ran some drills with the RS-15 to test it out. I am a little faster, shot to shot, under recoil thanks to the Vulcan reticle. One because it is so clear, and the other because the reticle just helps you find the dot faster. This is definitely a more useful sight on a handgun.

If you are looking into a red dot that can help you shoot better, the Primary Arms GLx RS-15 might be a good option. Partly due to its innovative ACSS Vulcan reticle. For new red dot shooters, it helps you find the dot and get used to it. For seasoned shooters, it helps you to find the dot faster. The GLx RS-15 even works for non-conventional uses like a shotgun. I have a hard time deciding what would be my favorite feature of the RS-15. Is it the Vulcan reticle, or the sights' clarity? Go check out the Primary Arms GLx RS-15 and see for yourself.

Firearms Insider Reviews - Key Points

Claim to Fame:

Quality red dot with the ACSS Vulcan reticle

Target Market:

Anyone wanting a quality red dot, but also those who will benefit from the ACSS Vulcan reticle

Features, Benefits, and Specifications of this product:

7075 Aluminum construction
Hardcoat anodized black
Top loading CR2032 battery compartment
5,000 Hour battery life with full reticle on medium setting
25,000+ Hour Battery life with dot reticle on medium setting
Side mounted buttons for brightness (13 settings with 3 night vision)
Red Dot Bright® ACSS Vulcan Dot reticle (3 MOA center dot with 250 MOA outer circle)
Multi-reticle select can be changed between circle/dot and just the dot
0.5 MOA windage and elevation adjustments
Autolive® functionality
Waterproof and shockproof construction
Multicoated lens
C-More footprint which is very similar to the Delta Point Pro footprint
Includes GLOCK MOS compatible mounting plate
Length: 1.84"
Weight: 1.11 oz.
Aperture diameter: 26x20mm
Lifetime warranty

What other aesthetic options or finishes are available?

Dot only version

What others are saying?:

5 out of 5 stars at primaryarms.com

SUPERB RDO WITH DIRECT FITMENT ON SIG PRO-CUT SLIDE

This optic is my third with the ACSS Vulcan reticle, but first PA-branded open reflex (others are HS 507k & 507c). I've become a real believer in this reticle, in either red or green.

Target and sight acquisition are super-fast and consistent -- intuitive, too, once a little muscle memory is achieved. For me, it also had a minimal learning curve, with the added benefit of presentation depth feedback, making it simple to verify the gun is in the correct position for each round fired.

Too far away, the 250 MOA outer ring disappears. In too close, the outer ring circles the 3 MOA dot. At just right, the outer ring guides the dot to perfect target alignment. It's a system beneficial to both experienced shooters and new RDO users, and it just plain works.

This optic, like the HS RDOs, checks all the right feature boxes too, including shake awake, top-mount battery and side-mount brightness.

It’s a real winner. A+ performance and value.