GLOCK 20 Gen5 MOS 10mm Handgun  – 10mm Perfection?

The Glock 20 Gen 5 MOS might be the perfect 10mm handgun; between its capacity, modularity, and flawless reliability, it’s a tough act to top. But the 10mm Glock has been around for a long time, is it still the top dog for big-bore blasters on a budget? Let’s take a closer look at the Glock 20 MOS Gen 5 and find out.

GLOCK 20 Gen5 MOS 10mm Handgun

The Glock 20 MOS Gen 5, like all Glock semi-automatic handguns, is a locked breech, magazine-fed handgun that feeds from stagger-column 15-round magazines and utilizes a polymer frame. What really separates this model from the others is its use of the ultra-potent 10mm Auto round. Developed in 1983, the cartridge was adopted by the FBI in response to the 1986 Miami Shootout, where the issued 9mm, 38 special, and 12-gauge firearms proved incapable of stopping two assailants armed with superior weapons. In effect, the FBI’s adoption of 10mm auto was meant to give agents magnum stopping power without the limited capacity and slower reloads of a revolver.

As far as terminal ballistics, the 10mm Auto is a resounding success; It produces nearly double the muzzle energy of a 9mm round. But most gun designs of the era still restricted the magazine capacity of guns chambered in 10mm, to just ten or fewer rounds. This can be seen on the now famous Bren Ten of Miami Vice fame and the FBI-adopted Smith and Wesson 1076.

Both if these guns have their merits, but they’re held back by limited capacity and heavy overall weight. Glock’s response to these guns came in 1991 with the introduction of the second-generation Glock 20. With a 15-round standard magazine capacity and dramatically lighter overall weight, the 20 was an instant hit with 10mm fans.

Since then, the engineers at Glock have further developed the 10mm Glock into a modern magnum fighting pistol equally at home by the bedside of a sleeping homeowner or on the hip of a hunter tracking dangerous game. That said, the Glock 20 is more than 30 years old, let’s talk about how the lightweight blaster has evolved.

G20 MOS Gen 5 Differences

The biggest and most apparent difference between the original Glock 20 and the Gen 5 MOS is the inclusion of an optics cut on the rear of the slide. This cut allows mounting an RMR-footprint micro reflex sight to the included plate after removing the polymer cover. As far as the generational differences from Gen 2 to Gen 5, they’re too numerous to list here, but here are the most important differences from the previous generation to the current one.

The standard 4.6-inch polygonal-rifled barrel has been replaced with a Glock Marksman Barrel, which provides better accuracy due to tighter tolerances and sharper rifling. The slide around this barrel is now finished in an nDLC coating that looks similar to a cross between the shiny Teflon-like finish of Gen 3 pistols mixed with the more matte dark Parkerizing of later models. While the color and texture might be different, they’re all nearly impervious to rust and wear caused by use. Another noteworthy added feature is the include ambidextrous slide stop that makes manipulating the gun just as easy for South Paws as the rest of us.

Below this, the grip has been redesigned again to exclude the old molded finger grooves in favor of a highly textured grip with a flared magazine well that also doubles as a point of retention like a pummel on a sword. Lastly, the baseplates on the magazines have been slightly enlarged to aid shooters in extracting them when their hands are wet or oily.

Glock 20 MOS – What’s in the Box?

Like all Glock handguns, the Glock 20 ships in a hard case lovingly referred to as ‘tactical Tupperware that contains the pistol, three backstraps, three magazines, a site plate (and mounting hardware), as well as a standard cable lock. All of this is pretty standard, but I wanted to give props to Glock for including three magazines with their guns. As someone who likes to have enough magazines not to reload them during a competition, the fact that Glock handguns are still affordable and ship with three mags is a huge plus. The only thing Glock could have included to make the gun, even more ready-to-rock out of the box would be a holster. But given how personal a holster is, and how many are available to fit every need a shooter has, they can’t be faulted for this.

GLOCK 10mm Recoil & Performance

I fired 500 rounds of various loadings of 10mm Auto through the Gen 5 MOS Glock 20 for the review, and I had some very big surprises in store for me.

First off, I expected the lightweight pistol to have vastly more recoil than it did. I did all the testing of this pistol while I had a pretty bad case of carpel tunnel syndrome in my right hand, and I was able to blast away for several magazines without pain. Keep in mind, I was running full-power 10mm Auto ammo exclusively throughout the test – so this is very telling.

What didn’t surprise me was how reliable the Glock 20 MOS was. Just like my old third-generation Glock 17, this new fifth-gen Glock 20 didn’t encounter a single malfunction throughout the entire testing procedure. I tried jacketed hollow points, ball, and wadcutter ammo, and all of the rounds fed and fired without a hitch. As far as accuracy, the Glock 20 proved precise enough to easily engage man-sized targets out to 100 yards, while running my competition plate rack was a breeze.

GLOCK 20 Gen5 MOS 10mm Handgun Worth a Buy?

To be honest, I wasn’t expecting much from the gun when I first got my hands on it. It’s not the fanciest or most high-speed, low-drag option on the market. What the Glock 20 MOS is, is unwaveringly reliable, perfectly accurate, and remarkably soft-shooting despite its use of big bad 10mm rounds. If I had to own just one 10mm Auto pistol to take with me while hunting dangerous game or to leave on my nightstand, it would 100% be the Glock 20 MOS Gen 5, especially with an MSRP of around $650 with street prices lower for thrifty shooters.

Complete Specifications for the GLOCK 20 Gen5 MOS 10mm Auto Handgun

Specifications

• Model GLOCK 20 Gen5 MOS 10mm Auto Handgun
• Model Number PA205S203MOS
• UPC 764503054273
• Brand GLOCK INC
• Action Pistol
• Capacity 15+1
• Barrel Length 4.61in
• Finish Black Nitrite
• Grips Textured With Changeable Backstraps
• Sights White Dot & Outline
• Weight 30.71oz
• Cartridge 10mm Auto
• Color Black
• Features Gen 4
• Frame Size Fullsize
• State Compliance Colorado Compliant
• Type Centerfire

Click here to download find the GLOCK 20 Gen5 MOS 10mm Auto Handgun manual.

About Jim Grant

Jim is one of the elite editors for AmmoLand.com, who in addition to his mastery of prose, can wield a camera with expert finesse. He loves anything and everything guns but holds firearms from the Cold War in a special place in his heart.

When he’s not reviewing guns or shooting for fun and competition, Jim can be found hiking and hunting with his wife Kimberly, their son, and their dog Peanut in the South Carolina low country.