Glock G40 MOS: An Optic-Ready 10mm Powerhouse

by
posted on July 14, 2021
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
Glock G40 MOS

Glock introduced its Gen 4 G40 at the 2015 Shooting, Hunting and Outdoor Trade Show. The polymer-framed semi-auto pistol sports the familiar businesslike looks of the company’s other offerings, but this one stood out from the others.

For one thing it had a 6.02" barrel hiding under a long slide (9.02 inches long, to be precise). It also came with the company’s brand-new Modular Optics System (MOS), which made mounting red-dot or reflex sights on the gun fast and effortless—a money- and time-saving virtue enthusiasts have come to appreciate. Glocks with the system ship with their slide milled for optics and base plates that fit the most popular electronic pistol sights are included. The combination makes anchoring an optic DIY, rather than one requiting gunsmith intervention.  

The handgun’s overall is 9.49", a rather cumbersome figure for duty or carry. The setup is ideal for hunters, though, who are more interested in wringing the last bit of performance possible out a cartridge than concealment, and usually prefer an optic over iron sights.

The G40 may not be Glock’s best-known handgun, but it continues to be a popular choice among enthusiasts, for good reason. When B. Gil Horman reviewed one for American Rifleman shortly after its release, he concluded, “The Gen4 frames fit my hands more comfortably than the Gen3 models and the addition of the MOS feature is certainly a plus. The timing of the G40's arrival couldn't be better. Finally, we can enjoy a reasonably priced 10mm long slide with the rugged reliability of a Glock without the need for expensive aftermarket parts or gunsmithing.”

The G40 MOS is chambered in 10mm, magazine capacity is 15 cartridges and the magazine release is reversible. The modular backstrap allows owners to customize feel. The gun weighs 35.45 ozs. empty and—for those not interested in mounting an optic—the pistol ships with an adjustable, white U-notch sight at the rear with a white dot up front. Glock doesn’t list MSRPs, but the gun is running roughly $800 on several reputable FFL websites.

Latest

Crosman Raiden 01
Crosman Raiden 01

Affordable, Full-Auto Fun: The Crosman Raiden BB Gun

Over the past two decades, the world of BB guns has gotten way more sophisticated than the simple muscle-powered models of our youth. A case in point is Crosman’s new-for-2026 Raiden.

New Dragons: Managing Muzzle Flash From Today's Suppressors

Muzzle flash has always been an issue for those who employ firearms seriously, and with today's crop of suppressors, there are design elements to be aware of.

Gun of the Week: Mossberg 590R Chisel

For those who are seeking a shotgun that's a bit more heavy-duty, Mossberg's 590 line offers plenty of options, and one of the latest is the striking 590R Chisel.

The Armed Citizen® June 12, 2026

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

A Cathartic Journey Back to Midway Arms & the MidwayUSA Foundation

NRA CEO & EVP Doug Hamlin returned to MidwayUSA, a place he first visited decades ago in the early 1990s as publisher of Guns & Ammo magazine alongside the late, great Robert E. Petersen.

Review: Steiner MPS-C

The new Steiner MPS-C is the compact but rugged, closed-emitter optic we’ve all been waiting for.

Interests



Get the best of American Rifleman delivered to your inbox.