When Primary Arms offered to send their new GLx 2x prism sight out for review, I jumped at the chance. I had been looking for something to put on my 16” pistol caliber carbine, and this sounded perfect, especially since it was specifically designed for a 9mm PCC. This prism scope uses Primary Arms’ popular ACSS reticle with daylight bright illumination. The GLx prism is something different, that works quite well.

The GLx 2x prism has numerous features. All of which make it a great optic. The first is the ACSS Gemini reticle. This reticle was designed for the 9mm Luger cartridge in a pistol caliber carbine. The simple explanation of the ACSS reticle is that it’s an upside down horseshoe shaped circle with a center triangle aiming point. It also has ballistic drop compensation (BDC) built into the reticle. Below the reticle is a target ranging ladder. The horseshoe also acts as an 8.6 mph lead when shooting moving targets. I do wish the reticle had some sort of hash marks, on the horseshoe, to keep it lined up with the aiming point, when leading a target. The bullet drops and ranging are best described by Primary Arms’ diagrams. Sighting adjustments are done with capped turrets. Once unscrewed, the caps can be turned over to adjust the windage and elevation in 0.25” MOA increments.

Primary Arms uses multi coated low dispersion glass in the GLx. This glass gives the optic great clarity. I found that the view through the GLx is super bright and clear. The etched reticle is also very clear and defined. This is probably due to an adjustable diopter for getting the reticle perfectly clear and adjusted to your eyes. Because the GLx is a prism sight, there is eye relief. Primary Arms states the optimal eye relief is 3.7” from the optic. I found that the GLx is very forgiving in the eye relief department. I get a good sight picture with my eye only an inch away and all the way out at around 6 inches of eye relief. The reticle is still very clear and usable at both extremes.

The GLx’s illuminated reticle has 11 brightness settings. The first 3 can be used with night vision devices. The highest 2 are what is called “daylight bright”, and are bright enough to be used in bright sunlight. Yes, the reticle shines a bright red, even in direct sunlight. However only the horseshoe and aiming triangle are illuminated. The BDC and ranging portions are not. Because of the nature of prism sights, if you have an astigmatism, the illumination will not “starburst” out like a normal red dot will. My only complaint about the illumination is the adjustment dial, the detent clicks are mushy feeling and not crisp at all.

Battery life can be a concern for some people. Primary Arms gave the GLx what they call “AUTOLIVE” motion sensing technology. This greatly improves battery life from the single CR2032 battery. How you might ask? Well, it automatically shuts off the illumination after 3 minutes of inactivity and turns it back on when motion is detected. They say this gives a battery life of approximately 20,000 hours on the medium settings. The Autolive works extremely well. Everytime I pick up the rifle, the reticle is on. I tested the off function also, and it does turn the reticle off after around 3 minutes of sitting idle on a bench. I have left the reticle turned on for most of its life here, without any problems. Plus, if the battery does go dead, the GLx still has an etched reticle for you to use.

Some people might wonder why the GLx prism comes in a fixed 2 power. The fixed 2x gives a little better target identification. But it also still gives the shooter an option to shoot with both eyes open. It barely took me any time to get used to it. I found the GLx to be just as quick, transitioning from target to target, as my previously mounted red dot. Having twice the magnification, plus the ACSS reticle, made the longer shots easier also. I was consistently hitting a 12” steel plate at 200 yards using the BDC portion of the reticle. For close targets, I just put the triangle on the target and pressed the trigger. If you want more precision, on close targets, one can use the top point of the triangle.

The GLx sight comes with all the mounting hardware needed. For one, it comes with three spacers to get the correct optic height for your carbine. It also uses standard mini ACOG bases, so if you don’t like the supplied mounting options, you can choose someone else's mount. Primary Arms also supplies various screws for the mounting of the spacers and for other styles of mounts. A little tube of Vibra-Tite (thread locker), wrenches, and a cleaning cloth are also included.

I wouldn’t consider the GLx 2x prism to be on the large size for this type of optic. It leans toward the smaller side, but still larger than most of the red dots of today. The GLx is not a red dot, but I am using them as a comparison for size. Total length comes in at 5.3 inches. The total width is 2.3” inches because of the battery and brightness adjustment. Otherwise the tube is about 1.5 inches in diameter. Total height without any spacers is roughly 2 inches. It does weigh 11 ounces, so about twice what their 1x micro prism weighs, but the same as some other 1x prism sights. I thought the size and weight were about right for all the features the GLx has to offer.

The Primary Arms GLx 2x prism works very well for its intended purpose on a 9mm PCC. I really like the AUTOLIVE feature. The 2x is a good all around magnification for a 9mm rifle. The ACSS reticle is clear, easy to use, and packed with features. I would definitely check out Primary Arms’ optic line. They did a very good job on the GLx with the Gemini reticle.

Firearms Insider Reviews - 8 Key Points

Claim to Fame:

2x prism optic with horseshoe style ACSS Gemini reticle

Target Market:

PCC shooters that want something more than a red dot

FNBs (Features & Benefits of this product):

ACSS etched reticle
2x fixed power
11 brightness settings
Night Vision setting
Daylight bright red illumination
AutoLive motion activation
20,000 hr battery life
Uses 1 CR 2032 battery
5.3” long
Weight - 11.0 ounces
3.7” optimal eye relief
0.25 MOA adjustments
FOV - 42ft @ 100yds
Low, Med., & High spacers included
Mini ACOG mounting interface
IP67 waterproof - 1 meter for 30 minutes

What other aesthetic options or finishes are available?

5.56/.308/5.45 BDC, 7.62x39/300 BO BDC,

What others are saying?:

5/5 stars @ primaryarms.com

SHOCKINGLY AMAZING OPTIC

For a CZ Scorpion, this optic is perfect. As a member of the old eyes club, if its not a Prism sight, I can't see as clear as I need to, so red dots are off the table. I have tried many red dots, and they have a snowflake image when I look through them and they are 1X, so a 2X is much better for my needs. This optic is extremely clear. This is not quite a Trijicon, but at 1/3rd the price and with the ACSS Gemini 9mm Reticle, this is a fantastic optic, especially for PCC's. When they come out with a 3X GLX, I will buy it too.

Link to other reviews:

Nothing found on the 9mm version

Price point:

MSRP = $369.99

I need it now! Availability:

Primary Arms

Our Rating:

Pros:

AutoLive activation
Battery life
Clear optics
Etched reticle
ACSS reticle

Cons:

Brightness knob detents are mushy
Has Eye Relief, unlike a red dot
Weight

Score: 8.00 Great

Primary Arms is a sponsor of the Gun and Gear review podcast. This has no bearing on the review. It was rated on its merits and not the sponsorship.

Mean Arms came into the Pistol Caliber Carbine (PCC) market with an interesting idea. They made a 9mm insert for Magpul Pmags, called the “EndoMag”. This eliminates having to use a special lower receiver or magazine adapter. I was intrigued after we discussed them on the Gun & Gear Review Podcast. Mean Arms kindly sent one for review.

The Endomag is not your standard magwell adapter. First up, it goes inside a Gen 2 or 3 Pmag body. Just take your Pmag apart and set your spring and follower somewhere. Now, depending on where you live, cut the Endomag to the required magazine capacity. It has marks for 15, 20, and 30 rounds and comes in a 10 round configuration. The included instructions tell you how to do this and it is super simple. I cut mine to accept 30 rounds. Then all you need to do is slide the Endomag assembly into the Pmag body and install the floorplate. It is now ready to be used.

Before using the Endomag, it is recommended that you break it in. Basically, it involves testing to make sure the mag body doesn’t rub the bolt. Then testing cycling, by hand, with the Endomag installed. Again, the instructions are very useful here. I could feel the bolt rubbing a little on the one they sent me. I just did as instructed and have had no issues.

The Endomag has some great benefits, and a few that leave me wanting something else. I love the ability to load rounds just by pushing them down, much like a standard AR magazine. This is because the Endomag is a double column, double feed magazine, much like the Colt 9mm style magazines. The Endomag also features a last round bolt hold open feature. My biggest complaint about the Endomag is the built in ejector. It functions great, but takes some training to unload the firearm. One has to cycle the bolt back by hand to eject the live round. Then while the bolt is back, you have to drop the magazine. If you drop the Endomag out before cycling the action, the round will not eject, and thus just go right back into the firing chamber. Like I said, this is a training issue, but during a competition this could confuse some people and maybe even cause an unsafe condition. Besides this training issue, the Endomag doesn’t require any other learning curve. It is the same size as a standard magazine, therefore it fits in all your gear. All the rifle’s controls will also be the same, especially the magazine release button. I also noticed that the magazine spring, that Mean Arms uses in the Endomag, looks very much like the spring that came out of the standard Pmag. So much that I would guess it is the same spring. The EndoMag also lets one “try out” a PCC without having to purchase a lower receiver or magwell adapter. Of course you would still need a complete 9mm upper.

I used the Endomag a lot. As expected, it ran like a champ. If I had a failure, it was minor, because I don’t remember any. One of the nice features about installing the Endomag in a Pmag body is that you can mark the Pmag with “9mm” in the dot matrix! That way you have a better chance of not getting your magazines confused. As far as training with the Endomag, I give it a thumbs up. 9mm is cheaper than 5.56/223, and has about the same felt recoil. So you can get some good training in, for cheaper.

Mean Arms has a good idea with the Endomag. It has some decent features to aid in training. Goes into a magazine body that you probably already have, and works fantastic. I just had to get over the ejecting a round before dropping the magazine. If you think the Endomag is for you, go give one a try, they are inexpensive enough to see.