Pistol Review: GLOCK's 20V & 21V MOS

Apr 21
5 min read

For years, the Glock 20 and Glock 21 lived in a strange limbo. Beloved by the people who actually used them, perpetually overlooked by the company that made them. While the 9mm models got Gen5 upgrades first, MOS cuts, flared magwells, and all the attention that comes with being the center of the Glock universe, the 10mm and .45 ACP faithful waited. And waited. The Gen5 MOS versions of both eventually arrived, but always with the sense that they were catching up rather than leading.

With the V Series rollout, Glock has folded its big bore twins into the new product line as the G20V MOS and G21V MOS, and the result is two pistols that finally feel like they are standing on equal footing with the rest of the catalog. Same V Series internal improvements, same MOS optics-ready slides, same "this is the new baseline" energy that Glock is applying across the board. If you have been waiting for the right time to buy a full-size 10mm or .45 ACP Glock, that time has probably arrived.

What the "V" Means

The V Series represents Glock's latest product evolution, sitting between the Gen5 and the recently announced Gen6 9mm models. Glock has described the V Series as establishing a "baseline of products while simplifying processes," which in practice means a consolidated, streamlined lineup with internal improvements focused primarily on the slide and trigger mechanism. The most discussed change involves modifications to the firing pin lug, which is smaller and thinner than on Gen5 models, along with a redesigned slide cover plate and updated internal channel geometry. Trigger pull remains in the neighborhood of the Gen5's roughly 4.5 to 5.5 pounds.

These are not cosmetic changes. They represent a genuine internal redesign, and one practical consequence is that current Glock Performance triggers will not function in V Series guns. Most external accessories, including sights, magazine base plates, holsters, and guide rods, carry over from Gen5 without issue.

The V Series began shipping in December 2025, with availability staggering through early 2026. Notably, while the 9mm V Series models shipped without MOS cuts (with the Gen6 handling that role), the G20V and G21V are among the only V Series pistols that retain the MOS optics-mounting system. For shooters who want a factory optics-ready Glock in something bigger than 9mm, these two are the way in.

The G20V MOS: 10mm Done Right

The Glock 20V MOS is a full-size, striker-fired, polymer-framed pistol chambered in 10mm Auto. The 4.61-inch Glock Marksman Barrel (GMB) features enhanced polygonal rifling with a target crown for improved accuracy over earlier barrel designs. The slide wears Glock's nDLC (diamond-like carbon) finish, which is harder and more corrosion-resistant than the older Tenifer treatment. Front serrations, an ambidextrous slide stop lever, a flared magazine well, a reversible magazine catch, and interchangeable backstraps round out the Gen5-derived feature set. The pistol ships with three 15-round magazines.

The 10mm Auto has experienced a genuine resurgence over the past several years, driven largely by backcountry and bear-country carry demand. The Glock 20 has been the default recommendation in that space for decades, and with good reason. It is reliable in conditions that would choke fussier designs, it carries 15+1 rounds of a cartridge that can handle everything from whitetail to grizzly depending on load selection, and it has the kind of aftermarket support that comes from being the most popular 10mm pistol ever made. The V Series update does not reinvent that formula. It refines the platform the same way Gen5 refined the G17 and G19, giving the 10mm crowd the same fit-and-finish improvements the 9mm world has enjoyed since 2017.

Overall length is 8.07 inches. Weight is approximately 38.8 ounces unloaded. The slide is roughly 2.5mm wider than a standard 9mm Glock slide, which is worth noting for holster selection. The wider slide also contributes to a slightly heavier reciprocating mass, which helps manage the 10mm's recoil impulse.

The G21V MOS: .45 ACP, Still Standing

The Glock 21V MOS shares the same frame size, barrel length, and feature set as the 20V, but chambered in .45 ACP with a standard capacity of 13 rounds. Three magazines ship with the pistol. The same GMB barrel, nDLC slide finish, MOS cut, ambidextrous slide stop, flared magwell, and interchangeable backstraps all carry over.

The .45 ACP is not having the same cultural moment as the 10mm. It does not need one. The cartridge has been doing its job since 1911, and the people who carry it tend to know exactly why they prefer it. The G21V offers those shooters a modern, optics-ready, high-capacity platform with the same Glock reliability that has made the brand a default choice for agencies and civilians alike. Thirteen rounds of .45 ACP in a polymer frame with a red dot mounted on top is a serious defensive tool, whether it sits on a nightstand or rides in a duty holster.

The .45 ACP's lower operating pressure and subsonic velocity profile also make the G21V an appealing host for suppressor use. Thread a can onto an aftermarket barrel, load it with 230-grain hardball, and you have one of the quieter full-size pistol setups available.

Choosing Between Them

The G20V and G21V share the same frame dimensions, the same slide width, the same barrel length, and effectively the same external controls. They even weigh nearly the same. The choice between them comes down to caliber philosophy, and that debate has been running for longer than either of these pistols has existed.

The 10mm offers a flatter trajectory, higher velocity, more energy at distance, and the ability to push into genuine hunting and large-animal-defense territory with proper loads. It also recoils more sharply, costs more to feed, and benefits from a firm grip and deliberate shot placement.

The .45 ACP delivers a wider, heavier projectile at moderate velocity with a push-style recoil impulse that many shooters find easier to manage in rapid fire. Ammunition is widely available, and the cartridge's subsonic nature makes it a natural suppressor companion.

Neither is the wrong answer. Both are better in V Series form than they have ever been.

Final Thoughts

The Glock 20V and 21V MOS represent the most refined versions of Glock's big bore platform to date. They carry forward everything that made the originals dependable while incorporating the internal improvements and feature standardization of the V Series. For the 10mm backcountry carrier, the .45 ACP loyalist, the nightstand gun builder, or the shooter who simply wants a full-size Glock in a caliber that starts with something other than a nine, these two pistols deliver exactly what the V Series promised: the same gun you already trusted, built a little better, with optics capability baked in from the factory. That is not a revolution. It is just Glock doing what Glock does, which is iterating until there is very little left to complain about.