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.

Link to other reviews:

Nothing found as of publishing

Price point:

MSRP = $359.99

Retail = Same

I need it now! Availability:

Primary Arms

Our Rating:

Pros:

ACSS Vulcan reticle
Clarity
Autolive motion activation
Window Size

Cons:

C-More mounting footprint
Slightly higher price when compared to similar reticles in red dots

Score: 7.50 Good

Favorite Link: Primary Arms SLx 1x prism review

When I first learned about the new Primary Arms SLx RS-10 mini reflex sight, I was very interested. Then I received one, and was even more excited. This little, open reflex, pistol mounted red dot is everything they said it would be. Including a great price of $199.99.

Autolive in action

The SLx RS-10 is packed with features. It runs a 3 MOA red dot that is easily picked up. It has 11 brightness settings. Of which include night vision compatibility and daylight bright. I couldn’t try out the night vision setting, but the daylight bright setting is really bright, even in direct sunlight. You should have zero problems seeing the dot in any light. The RS-10 also has easy to use controls on the left side. These buttons are only raised slightly above the RS-10’s surface. Of course they control brightness as well as actual on/off. I say “actual” because the RS-10 features Primary Arms’ “Autolive”. The Autolive is an automatic on/off function that works fantastic. Just barely move the sight and the dot turns on. After about 3 minutes of zero sight movement, the sight turns off. Any teeny movement will keep the RS-10 on. Back to the “actual” on/off. To turn the sight off, as if you are going to store it for a long time, just hold the up and down buttons simultaneously for a few seconds and the sight will permanently turn off. Then to turn it back on, and into the Autolive feature, just hold either the up or down button a few seconds until the dot turns on. Primary Arms specs the battery life at 40,000 hours with a CR2032 battery. So if you change the battery out once a year, you should be good to go and never have the dreaded dead dot. If you couldn’t tell, I really like the Autolive feature.

Primary Arms also stuck some other features into the RS-10. For strength, they manufacture the housing out of 7075 aluminum. This is the same grade aluminum that quality AR receivers are made from, so it should be good to go. I really like the shape they chose for the housing and window. The rounded, almost square shape seems to draw my eye to the dot. I seem to find the dot much faster than other pistol mounted red dots. Primary Arms says the window size is 23mm and even if it is a smaller window than some brands, see the above comments. I mentioned battery life earlier, but the RS-10 does have a side loading battery tray. That means you can change the battery without having to remove the sight from your desired mounting platform, keeping your zero intact. Coming in at just over an ounce, the RS-10 shouldn’t weigh you down either.

Anymore, the mounting method for a reflex sight is very important. Mainly because one needs to know if it will fit on their handgun. The SLx RS-10 uses the fairly common Docter/Noblex footprint to directly mount to stuff. Primary Arms also includes a picatinny rail mount and a Glock MOS plate. That way if you aren’t mounting it directly to a pistol, you have some options. For instance, it would make a great 45 degree offset red dot for a rifle. I ended up mounting it on a Strike Industries Liteslide for a G19, as it has a multi optic mounting platform. The SLX RS-10 mounted in perfectly. Primary Arms decided to go with the Docter mounting footprint so they could use that CR2032 battery and have it side mounted. Since the battery is physically larger than other options, you end up getting more battery life out of it. For the small size of the RS-10, a different mounting footprint just wouldn’t work.

The SLx RS-10 is a great little red dot. This doesn’t come without a few tiny gripes. If you hold the RS-10 on target, and start shaking it a tiny bit, in a circle, the dot will galaxy out. So it literally looks kind of like a little galaxy inside the window. Does it bother anything? Nope, when shooting the pistol I didn’t even notice it. Even on moving and circling targets. Most people probably wouldn’t even notice it. I also would have liked to see it on a RMR footprint, but Primary Arms didn’t do this because of those “battery” reasons. I can understand this. Now, on a good note. Even for me, with my astigmatism, the dot is fairly clear. So those with normal eyes will see a nice crisp dot.

I am going to say this, the Primary Arms SLx RS-10 is currently my go to red dot pistol sight. This red dot impressed me more than I expected. I can find the dot easily. I haven’t destroyed it yet. Even if I did, it has a lifetime warranty. The size doesn’t get in the way. I’d say it is somewhere between one of the super small mini reflex versions and a Holosun 507. The RS-10 is always ready to go because of the “Autolive” feature. The click adjustments for windage and elevation make it easy to make adjustments, unlike other mini reflex sights that have no clicks. I ran this thing fairly hard and have had zero problems.

If you are looking for a mini reflex red dot, the SLx RS-10 from Primary Arms might be it. It is priced under $200. At that price, it’s a great deal for this feature packed red dot. With the Autolive function, you won’t have to worry about if the dot is on or off, because it will always be on. I don’t think you can go wrong selecting the Primary Arms SLx RS-10 mini reflex sight.