Tested: Glock 19 Gen5 MOS FS Pistol

posted on June 20, 2019

Glocks are among the best known and well-proven pistol platforms in existence. Since their introduction in the mid-1980s, Glock pistols have transformed the handgun market for armed professionals and citizens alike, and have become the bar against which other guns are measured, particularly with regard to rugged reliability. At writing, the basic Glock platform is in its fifth iteration, denoted “Gen5” by the Austrian maker and its Smyrna, Ga., based American arm. Each of the evolutions have been widely reported on by this and other publications, so rather than retread covered ground, this review will be confined to one model—the G19 Gen5 MOS FS—and focus specifically on several noteworthy features.

Despite appearing to be alphanumeric soup, one can learn a lot from Glock’s model designations. Being a Glock—sometimes abbreviated simply to “G” before the model number—the gun is sure to be a striker-fired, semi-automatic center-fire pistol feeding from a detachable magazine (fully-automatic variants such as the G18 do exist, but are not available to average consumers). Though some contract models do feature a manual safety, most commercial Glocks, including the subject of this review, rely on the company’s Safe Action System, comprised of three passive safeties: trigger safety, firing pin safety and drop safety. The model number, in this case “19,” was originally tied, sequentially, to Gaston Glock’s personal invention patents—i.e. the original Glock 19 was his 19th invention. Now those numbers indicate, roughly, the size, chambering and ammunition capacity for a given gun, the G19 being a compact pistol in 9 mm Luger featuring a 4” barrel and 15-round magazine.

We’ve already mentioned Glock’s various iterations, or Gens, and this being a Gen5 we know that the frame will feature a flared magazine well and no finger grooves, the slide has received an nDLC finish, lefties will appreciate the bilateral slide stop and reversible magazine release, and the barrel is Glock’s enhanced Marksman component. The “MOS” stands for Modular Optic System and refers to the slide’s topside cutout and corresponding mounting plates which facilitate the attachment of a miniature red-dot sight. Finally, “FS” refers to the guns front serrations which are intended to improve slide manipulation when loading the gun or press-checking to inspect whether a cartridge is present in the chamber.

Circling back to the frame and front slide serrations offers some insight regarding Glock’s current modus operandi. The frame is, as mentioned, the Gen5 configuration, though with one interesting change. Most Gen5 models feature a new semi-circular cutout at the base of the grip frame’s frontstrap, ostensibly to facilitate removing a stuck or stubborn magazine by allowing a finger to hook and pull the magazine’s baseplate. However, the cutout was not particularly well received and the Gen5 MOS models—released a year after the “base” configurations—have done away with it. Likewise, all Gen5 MOS models (at writing) also feature front slide serrations, previously a special-run feature or an aftermarket upgrade. The Gen5 MOS guns are interesting because they reflect the popularity—or lack thereof—of certain features, and Glock’s willingness to make changes based on consumer feedback. That the changes were made “mid-Gen” also indicates that the company may be more agile and responsive than in years past.

In terms of performance, the G19 Gen5 MOS FS yielded no surprises—it is, after all, a Glock. The pistol functioned without flaw, fed and fired a wide range of ammunition, and exhibited good accuracy and handling at the bench and in more dynamic drills. For the evaluation we mounted a Trijicon SRO with a 2.5-m.o.a. red-dot reticle using the provided hardware and screws from Trijicon’s RMR mounting kit. Throughout several hundred rounds of testing, the sight remained snuggly fastened to the slide and did not lose zero. With such a sight, accuracy potential is greatly increased. In fact, we decided to use targets with extra-small “bulls” because the optic’s reticle is a much finer aiming point than the typical pistol front sight. The benefits of the sight, however, were somewhat counter-balanced by the Glock’s trigger which, typical of Glocks and many striker-fired pistols, was no friend to deliberate, precision-style shooting, as is required by American Rifleman’s accuracy protocol. Make no mistake, accuracy was excellent: All loads tested averaged less than 2” for five, five-shot groups at 25 yds., and the combined average of the three test loads was 1.68”—very good for any pistol, and a credit to the Marksman barrel and red-dot sight. The testers nevertheless felt the gun was capable of even greater accuracy had the trigger been a bit smoother and lighter—of course, there are aftermarket components to address just such concerns. Overall, the Glock 19 Gen5 MOS FS seems to be a supremely reliable defensive pistol with a feature set reflecting the needs and desires of modern defensive shooters. Given the renowned platform has been refined throughout five-plus generations, and its utility can be further enhanced with the addition of a reflex-style optic, in our opinion this iteration of the Glock is the company’s best to date.

Glock 19 Gen5 MOS FS
Importer: Glock, Inc., 6000 Highlands Parkway SE, Smyrna, GA 30082; (770) 432-1202; us.glock.com
Manufacturer: Glock GmbH (Austria)
Chambering: 9 mm Luger
Action Type: recoil-operated, semi-automatic center-fire pistol
Slide: steel; black nDLC finish
Frame: polymer, Rought Texture, black
Rifling: hexagonal; 1:9.84” RH twist
Magazine: 15-round detachable box
Sights: white-dot front; white, square-notch rear
Trigger: striker-fired; 5-lb., 13-oz., pull
Width: 1.34”
Weight: 24 ozs. with empty magazine
Accessories: owner’s manual, lock, extra magazine
MSRP: $745
Overall Length: 7.28”
Barrel Length: 4.02”
Height: 5.04”

Additional Reading:
Video: Glock 19 Gen5 MOS FS 9 mm Pistol  
First Look: Trijicon SRO (Specialized Reflex Optic)  



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