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Primary Arms SLx Microdot 25 Gen 2 Optics Review
Primary Arms SLx Microdot 25 Gen 2 Optics Review
Primary Arms SLx Microdot 25 Gen 2 Optics Review
Chris Fortenberry Last modified Mar 12th 2023

Introduction

Primary Arms is one of several players in the competitive market for red dot optics. Primary Arms SLx product line is their answer to offerings by Holosun, Sig, and others. Primary Arms has several options with varying features and price points.

One of the Primary Arms entries in the red dot market is the SLx Microdot 25 Gen 2. Primary Arms made this a full-featured red dot.

We will examine the Primary Arms SLx Microdot 25 Gen 2 and let you know what we like about it and what we wish they would have changed. So pull up a chair and check out the Primary Arms SLx Microdot 25 Gen 2.

Primary ArmsSLx Microdot 25 Gen 2 Review

Primary ArmsSLx Microdot 25 Gen 2

Red dot optics solve several issues that can be experienced by shooters using traditional iron sights. One major benefit of red dot optics is they can help the shooter acquire the target quicker than iron sights. The “red dot” is easier to find and place on the target, especially in low-light situations.

Red dot optics are also easier to use with both eyes open. As a shooter, learning to shoot with both eyes open permits better situational awareness and helps minimize the risks with shooting with one eye closed.

Cutting off half of your field of view is not a good idea in a home or self-defense scenario. Also, in my experience, shooting with both eyes open is less fatiguing than shooting with a single eye.

Red dot sights, like the Primary ArmsSLx Microdot 25, provide a less restricted field of view than iron sights, ultimately allowing most shooters to use their firearms more accurately and safely than traditional iron sights.

This isn’t to say there aren’t drawbacks to red dot sights. Battery life is a major factor to consider when adding a red dot sight to your firearm.

Forbid that a self-defense situation arises, but you forgot to turn off your red dot sight, and the battery is dead. This is an issue the Primary ArmsSLx Microdot 25 solves with its Auto Live feature, but more on that later.

Iron sights are simpler than a red dot and not as prone to failure since they are significantly more basic. That being said, a properly maintained red dot sight is a fantastic accessory, and one most shooters should take advantage of.

Specifications

Length3 inches
Weight6.5 ounces
Magnification1x
Objective Lens Diameter        25mm
Adjustment Graduation.5 MOA
Windage Adjustment50 MOA
Elevation Adjustment50 MOA
Night Vision Compatible        Yes
Reticle ColorRed
Reticle PatternACSS-CQB
Illumination Controls11 Brightness setting including 2 NV settings
Battery TypeCR2032
Battery Life10,000 – 25,000 hours (50,000 hours with 2 MOA dot version)

Pros & Cons

Pros
  • Primary Arms lifetime warranty
  • Auto Live battery saving technology
  • Clear glass
  • High quality materials
  • Included risers and accessories
Cons
  • Larger footprint than some competitors

Design and Construction

The Primary ArmsSLx Microdot 25 Gen 2 is a neat package. When you take it out of the box, it looks good and feels good in the hand. It isn’t as compact as some other red dots, but the size was not so large as to become negative.

Primary Arms made the Gen 2 version of their SLx Microdot out of high-quality aluminum, and the optic feels durable.

I did not torture test the optic, but I feel completely confident in the red dot and its durability. It will hold up to more abuse than most users will expose it to.

Additionally, the Primary Arms lifetime warranty is solid should you experience an issue with your Primary ArmsSLx Microdot 25.

The Primary ArmsSLx Microdot 25 Gen 2 comes with multiple risers and spacers. The standard riser gives a 1.41-inch center-line height. There are two spacers included as well.

The thin spacer and riser give a 1.535-inch center-line height, and the thick space and riser have a 1.64-inch center-line height. The included low base riser has a .96-inch center-line height.

Primary Arms SLx Microdot 25 Gen 2 parts from manual
Mounts and Risers (Photo Credit: Primary Arms)

The Primary ArmsSLx Microdot 25 Gen 2 has .5 MOA adjustments using top and side-mounted adjustment knobs for a total of 50 MOA adjustments.

Primary Arms SLx Microdot 25 Gen 2 controls
Primary Arms SLx Microdot 25 Gen 2 controls from above

Magnification & Reticle

The Primary ArmsSLx Microdot 25 Gen 2 is a 1x magnification red dot sight. The glass on the red dot is clear and doesn’t distract from the sight picture.

Primary Arms SLx Microdot 25 Gen 2 reticle
ACSS CQB Reticle (Photo Credit: Primary Arms)

The Primary ArmsSLx Microdot 25 Gen 2 is available with two different reticles.

The model we reviewed is the Primary ArmsSLx Microdot 25 Gen 2 with ACSS CQB reticle. The ACSS CQB reticle features three BDC dots under the chevron. The dots allow the shooter to have 600 yards of bullet drop compensation for 5.56 NATO and 7.62 NATO.

The manual for the Primary ArmsSLx Microdot 25 Gen 2 includes bullet drop compensation for many other calibers as well. These calibers include .22lr, 7.62×39, Subsonic 300 BLK, and 9MM with carbine length barrels.

Primary Arms SLx Microdot 25 Gen 2 reticle test
ACSS CQB Reticle

The Primary ArmsSLx Microdot 25 Gen 2 has another model that sports a 2 MOA red dot reticle similar to those found on many red dots. The SKU for the 2 MOA model is PA-SLX-MD-25-G2. It comes in about $50 cheaper than the ACSS CQB reticle version.

Primary Arms gave the SLx Microdot 25 Gen 2 a super bright, high-efficiency LED. This gives the sight 11 brightness settings including 2-night vision settings.

The 25mm aperture on the Primary ArmsSLx Microdot 25 Gen 2 was very clear. It offered a wide field of view, wider than some older 30mm red dots. This allowed Primary Arms to keep the weight and overall footprint of the optic down.

At the Range

Reliability

The Primary ArmsSLx Microdot 25 Gen 2 was reliable for me.

I put the sight on an AR pistol, carried it around my farm, took it to the range, put rounds on target, and kept it ready to go in my house. Never once did I have an issue where it failed to turn on or experienced a loss of zero.

Accuracy

I experienced good accuracy when using the Primary ArmsSLx Microdot 25 Gen 2. The red dot was easy to zero, and once zeroed, I was able to consistently put shots on the inner rifle at one hundred yards and ring steel on almost every shot at two hundred yards.

Overall Looks and Feel

The Primary ArmsSLx Microdot 25 Gen 2 is a good-looking and good feeling optic.

As soon as I pulled the sight out of its box, I was impressed. It is a bit bigger than something like a Sig Romeo5 or Holosun 407, but it wasn’t so big as to look unsightly. I found it to be a very attractive red dot and think it fit well with the aesthetic of the AR pistol I put it on.

Primary Arms SLx Microdot 25 Gen 2 mounted on ar pistol
Primary Arms SLx Microdot 25 Gen 2 mounted on ar pistol
Primary Arms SLx Microdot 25 Gen 2 mounted on ar pistol controls

Features

ACSS CQB Reticle

I have already discussed the ACSS CQB reticle above, but it is important to mention it again.

The ACSS CQB reticle has several things going on at the same time. First is the horseshoe at the top. This is great for shotguns and quick target acquisition at close range.

The main chevron and BDC dots allow quick adjustments to shoot at varied distances, and the main chevron can compensate for windage and elevation.

One of the biggest issues I did experience when first using the red dot was picking out the BDC dots. Initially, the dots just appeared to be a line extending down from the main chevron of the sight.

After some practice, I could pick the dots out and did not continue to experience the “line” effect I did initially. Whether this “line” effect just requires more training to overcome or will become a consistent issue remains to be seen.

Auto Live

I like Auto Live technology Primary Arms included in the Primary ArmsSLx Microdot 25 Gen 2. It was convenient to have the optic go to sleep when I wasn’t using it and then quickly wake up when I grabbed my AR and was ready to shoot again.

Battery life is a major failure point for red dot sights, and the Auto Live feature will help extend the battery’s life in the Primary ArmsSLx Microdot 25 Gen 2.

Riser and Spacers

I can be very picky about the height of my red dots.

The standard riser was already a height I liked, so I did not use the included spacers or the low riser. That being said, what is a good height for me might not be a good height for every other shooter or firearm. I like how Primary Arms included multiple options with the Primary ArmsSLx Microdot 25.

How We Tested

I carried the Primary ArmsSLx Microdot 25 Gen 2 around my farm on my AR pistol and took the same pistol to the range for an extended range session.

Score Card

Reliability (10/10)

The Primary ArmsSLx Microdot 25 Gen 2 was reliable during my testing and usage.

Ergonomics (10/10)

The Primary ArmsSLx Microdot 25 Gen 2 felt good in my hand when I took it out of the box. Mounting to my AR was quick and simple, and I had no parallax or eye relief issues.

Customization (9/10)

At the time of writing, the Primary ArmsSLx Microdot 25 Gen 2 is only available in black. For me, that is not an issue, but for someone looking for a specific design aesthetic for their AR, that could be an issue.

Appearance (10/10)

The Primary ArmsSLx Microdot 25 Gen 2 looks good. I can’t think of any firearms I own that have Picatinny rails I would not put them on.

Value (7/10)

This is where I feel the Primary ArmsSLx Microdot 25 Gen 2 could do better.

Considering that some competitors can be found for $80-$100 less than the Primary ArmsSLx Microdot 25 Gen 2 I ACSS CQB reticle version, I am not sure the added features justify the added price.

Comparing the 2 MOA version’s price to Primary Arms’ main competitors, the Primary ArmsSLx Microdot 25 Gen 2 is, in my opinion, a more fair comparison for value.

Accessories

Primary Arms SLx 3x Micro Magnifier

Primary Arms SLx 3X Micro Magnifier

Adding a magnifier could be a good choice for some shooters. The Primary Arms SLx 3x Micro Magnifier is a good option if that is what you want to add magnification to your firearm.

Streamlight ProTac 2.0

Streamlight ProTac 2.0

A flashlight would be another good accessory to pair with your Primary Arms SLx Microdot 25 Gen 2. The Streamlight ProTac 2.0 is a good choice.

Alternatives

Sig Romeo5

Sig Sauer SOR52001 Romeo5 1x20mm Compact 2 Moa Red Dot Sight, Black

The Sig Romeo5 is compact, 1x, red dot optics. It features a 2 MOA reticle and provides excellent value. Optimized for use on rifles, carbines, shotguns, and large handguns.

The Sig Romeo5 competes with the 2 MOA reticle version Primary Arms SLx Microdot 25.

Check out our Sig Romeo5 review for more information.

Holosun 510c

HOLOSUN - HE510C-GR Open Reflex Optical Sight with Super Green LED (2 MOA Dot, 65 MOA Circle)

The Holosun 510c is an open reflex sight. It features a robust reticle that competes with the Primary Arms SLx Microdot 25 Gen 2 ACSS CQB reticle.

It is optimized for use on rifles and carbines. It has a solar-powered backup and shake-awake features.

Last Words

The Primary Arms SLx Microdot 25 Gen 2 is a solid red dot optic with great features. The ACSS CQB reticle, Auto Live technology to save battery life, and quality construction make for a full-featured red dot.

Primary Arms stands by its products, as demonstrated by its lifetime warranty. This gives it a leg up on cheaper red dot sights since many manufacturers back their red dots with one-year warranties.

The Primary Arms SLx Microdot 25 Gen 2 is a full-featured red dot. It will meet your needs and perform at a high level.

The ultimate decision whether to buy Primary Arms SLx Microdot 25 Gen 2, especially the ACSS CQB version, or one of its cheaper competitors will come down to what you are looking for with a red dot.

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