Mepro M22 Light Module Kit Review

In today’s article, Dr. Will Dabbs reviews the Light Module Kit for the Mepro M22 red dot sight. Why you might want a supplemental light source for your self-illuminating rifle optic is just one of the questions Dabbs addresses in his article. The Mepro M22 Light Module Kit was provided by the company for review.

Self-loading guns shoot pretty much the same way today that they did a century ago. The materials science and manufacturing efficiency have advanced astronomically, to be sure. However, the same basic concept wherein the energy from an exploding cartridge is used to cycle a self-loading action remains monotonously unchanged over decades. What is literally unrecognizable from a short generation ago is the way we sight our firearms.

The Mepro M22 Light Module Kit offers additional reticle illumination when transitioning between disparate lighting conditions. Image: Meprolight

In eras past, the state-of-the-art was a steel post front and adjustable peep or notch rear sight. Untold millions of tactical rifles shot both straight and true using that same basic timeless concept. That was all just physics.

Establish two points that are reliably parallel to the bore of your weapon, orient those two points toward a distant target, and take into account whatever parallax might result from the offset between the sights and the bore axis. Given appropriate technique, the gun will subsequently hit the target, all other lesser considerations notwithstanding. It’s not like that anymore.

Mepro M22 light module review Will Dabbs photo — The Light Module Kit bolts onto the exterior of the Mepro M22, giving the system the streamlined appearance of a single unit.

Nowadays you can’t eat at the cool kids’ table at the local range unless you have something sparkly and electronic perched atop your favorite tactical heater. Where early versions were the size of a hot dog and took batteries with an abysmal service life, today’s offerings are small enough to ride comfortably on your favorite deep-cover pistol and will run for ages on a basic button cell. The specific particulars are nonetheless sufficient to drive a thriving industry.

Variety Is the Spice of Life

All these modern gun sights require a source of power. The simplest of the lot take batteries. However, these batteries invariably discharge over time. It is surprisingly difficult to remember to keep those things fresh. I resolve to swap the batteries out on my utility guns every other birthday, but I’m still not as reliable doing that as I should be. There have been a couple of times wherein I grabbed my home defense pistol and found that the red dot sight had perished due to rank neglect.

Springfield Hellion with Mepro M22 light kit mounted — The author mounted a Meprolight M22 and Light Module Kit on his Springfield Armory Hellion rifle.

There are solar-powered alternatives that seem to work well. Some incorporate fiber optic elements that draw in ambient light and concentrate it into an aiming point. Others sport photovoltaic cells that convert light into electricity to power a visible diode. However, an unsettling percentage of defensive engagements occur during periods of limited visibility. If the gun is stored in the dark, as most are, you might have a problem when you need to use it.

A third alternative is legit nuclear power. Tritium, or hydrogen-3, is a radioactive isotope of hydrogen with a half-life of about 12.3 years. Tritium is the heaviest particle-bound hydrogen isotope. It is defined by a nucleus consisting of one proton and two neutrons. Though profoundly rare in nature, Tritium is produced artificially via the irradiation of lithium-bearing ceramic pebbles in nuclear reactors. Tritium is naturally radioluminescent and is used in watch faces, gun sights, tools, and, curiously, as nuclear fuel for hydrogen bombs.

installing light module kit on Mepro M22 — The Light Module Kit comes in two halves and has a precise fit over the body of the Meprolight red dot sight.

As it relates to gun sights, the 12.3-year half-life of Tritium means that its innate radioluminescence naturally degrades over time. The big appeal is that Tritium sights do not require batteries. However, Tritium-powered sights have a finite shelf life. Typically after about a decade, these sighting elements tend to lose their luster.

So, those are your choices. Each has its own unique benefits and liabilities. Choosing among them represents an invariable compromise. However, to paraphrase Tony Stark, what if you could just have everything? Meprolight can get you there.

The Tricked-Out M22

Founded in 1990, Meprolight draws from a deep well of experience producing advanced optical gunsights for the IDF (Israel Defense Forces). Their tactical gear is invariably well-reasoned, effective, and tough. The end result of some 34 years of mechanical evolution is the Meprolight M22. [Don’t miss Andy Grossman’s Meprolight M22 review for additional information on this red dot sight.]

author shooting Springfield Armory Hellion with Mepro M22 optic with light module kit — Meprolight offers rugged gear for the civilian market, as the company’s equipment has been battle tested for decades with the IDF.

The M22 is a state-of-the-art self-illuminating reflex red-dot sight. It is powered by both a fiber optic system as well as a Tritium lamp. Reticles can be had in either red or amber. Users can select either a bullseye or chevron design as well. The sight is 100% self-illuminating and automatically adjusts for ambient light conditions. It is also compatible with NVGs and external magnifiers.

Everything about the M22 is designed for the battlefield. The housing is rugged and indestructible, while the throw-lever mount makes set-up a snap. Once you get the M22 zeroed, it is stupid proof. Just put the reticle over the target. However, that’s not to say the rig is absolutely perfect.

Everybody Has a Weakness

In hard dark or conditions of decent ambient light, the M22 runs great without batteries. Once you take its measure, nothing is faster. However, there are certain narrow circumstances wherein the Tritium lamp can be overwhelmed. The most common is moving from a dark area to a bright area. If orienting your firearm indoors to outdoors, excessive ambient light on the target can obscure the reticle. For those specific circumstances, Meprolight offers their bolt-on M22 Light Module Kit.

light module for Mepro M22 — The two sides of the Light Module Kit are shown here. They have the appropriate cuts and ports to allow for the normal operation of the M22.

The Mepro M22 light module kit consists of a polymer shell that fits snugly around the M22 housing and includes a battery-powered booster with three manual brightness settings. The light module runs off of a ubiquitous CR2032 battery and enhances the reticle brightness for those times when ambient conditions are not favorable for a solar-powered or Tritium rig. With the light module kit installed, the M22 really is everything for all users.

Mepro M22 with M22 light module mounted on rifle — Mounted on the author’s Hellion rifle, the M22 is shown here fitted with the Light Module Kit.

The light module kit is naturally designed so as not to interfere with the function of the host sight. The base M22 still draws in ambient light via its fiber optic system and provides Tritium-powered illumination independent of batteries or ambient conditions. It is simply that this battery back-up bumps everything up a bit for those rare circumstances when you need that little boost.

Practical Tactical

In practical application, the M22 with a light module installed is indeed stupid-proof. The host M22 requires no external manipulation beyond basic zeroing. The light module operates off of a simple pushbutton control. Batteries can be changed without dismounting the sight. There is no magnification, and the optical quality is as good as mankind can produce. As a result, the field of view remains clear and unobstructed for fast target engagements.

I mounted the tricked-out M22 on top of my Springfield Armory Hellion bullpup modern sporting rifle. The sight would also be right at home on the SAINT or SOCOM M1A. Should you wish to reach out a ways, it is a simple chore to set up a pivoting magnifier behind the optic. Meprolight makes those as well. When moving tactically indoors or at modest ranges outside, nothing is better. Additionally, because this rig covers literally all the technical bases, it is as close to maintenance-free as any optic on the market today.

It’s a buyer’s market for tactical glass these days. Price points run from paltry to astronomical with everything in between. Sporting an MSRP of $499.99, the Mepro M22 falls right about in the middle for truly pro-grade glass. The light module kit is another $125. Seems like a great deal to me.

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