Glock MOS – Modular Optic System

    The new Glock MOS – Modular Optic System handguns were ready to fire at the Industry Day at the Range. Recognizing an increasingly popular trend towards red dot optics for handguns, the Glock MOS handguns provide shooters a variety of options for using many of today’s most popular red dot handgun sights, using an intuitive design.

    The Glock MOS handguns offer a variety of options for several of today's most popular red dot optics.

    The Glock MOS handguns offer a variety of options for several of today’s most popular red dot optics.

    The premise and design of the Glock MOS is actually well done. Glock engineers recognized that with handgun shooting distances typically being in such close quarters, bore-to-sight off-set issues can have dramatic effects on shooting accuracy. Simply adding a mounting rail or other system on top of their Glock handguns would only exacerbate the problem. In other words, having a red dot sight so far above the bore on a handgun really messes with the whole point of red dot optics – point and shoot. To tackle that issue, Glock engineers dug into the slide itself to provide as low of a setting as possible.

    This Glock MOS pistol has the Leupold Delta Point red dot optic mounted.

    This Glock MOS pistol has the Leupold Delta Point red dot optic mounted. Notice the slim mounting plate just below the optic.

    Instead the Glock engineers cut into the slide just enough to allow interchangeable mounting plates to be installed. This provides enough of the original slide metal to sustain structural integrity and prevent moisture or debris from entering the trigger group. The fitting is very secure.

    The cut in the slide is shallow, and does not expose the firing pin group. The front of the cut does get very close to the extractor but the Glock guys said engineers were confident that the strength of the metal used in the slide, and the Glock Melonite-type finish (no longer Tenifer due to US EPA regulations on some hazardous by-products) would endure heavy use. Unfortunately, even with the cut into the slide, and the relatively slim profile of pistol red dot optics, the standard Glock sights will not co-witness with the red dot optic like many rifles can.

    The Glock MOS handguns will come with (5) interchangeable mounting plates:

    • Plate 00 – This is the base cover for when no red dot optic is mounted
    • Plate 01 – Fits EOTech, Docter, Insight, and Meopta optics
    • Plate 02 – Fits Trijicon RMR
    • Plate 03 – Fits C-More
    • Plate 04 – Fits Leupold Deltapoint

    The versatility of the MOS system is a great design feature that allows shooters to update or modify their red dot optic selections if desired. Simple mounting tools are all that are needed, and sights can be switched out in a few minutes. For those who purchase a Glock MOS handgun, Glock will provide a brochure that matches the proper mounting plate to the red dot optic of your choice. At the Industry Day at the Range I observed Glock MOS pistols with Leupold Deltapoint and Trijicon RMR optics.

    A Glock MOS with Trijicon RMR red dot optic.

    A Glock MOS with Trijicon RMR red dot optic.

    Shooting the Glock MOS handguns was a nice transition from the standard 3-dot sights. Acquisition of targets was quick, as to be expected, and finding the dot after recoil was nearly seamless. Accuracy at 15-yards was impressive. Glock explained that their system will provide as much stability as possible for the red dot optic to do its job. Additionally, it was reported that red dot optics advancements are providing a much better maintenance of zero and long-term durability than early models suffered from.

    Currently the Glock MOS is only available in the following models, and has an MSRP of $699:

    • G34 – 9mm
    • G35 – .40 S&W
    • G40 – 10mm
    • G41 – .45 ACP.

    I asked if there would be the option to simply purchase a MOS slide and mounting plates to switch out with a shooter’s existing Glock handgun. And that’s where Glock drops the ball – Nope! To have the Glock MOS you must purchase an entirely new handgun. Hopefully, as the MOS line expands, that restriction will not remain. However, like many, I’ve held my breath for Glock before, and I’m not too interested in passing out.

    There are already several Level I holsters on the market that will accept the Glock MOS handguns. Talking to the Glock reps and some reps from Safariland, there will be Level II holsters ready for the Glock MOS to satisfy law enforcement or government users needs. Level III holsters are still a bit down the road, but will likely be developed as demand grows.


    Aaron is a life-long firearm enthusiast and hunter. He has been a police officer for nearly 19 years, and currently is a Sergeant in Special Operations. He has served on the department’s SWAT Team for 14 years, with 8 years as the Sniper Team Leader. When not fussing over fractions of inches, and gut-less wonders, he can usually be found sipping from a ridiculously large coffee mug. Aaron is also the editor and main writer at