Every Glock Model Explained: 2026 Guide to Numbers, Calibers & Generations

What Does the Glock Number System Actually Mean?

If you’ve ever stared at a Glock display case and wondered why there’s a Glock 17, a Glock 19, and a Glock 45 that somehow isn’t chambered in .45 — you’re in good company. The Glock number system is one of the most misunderstood naming conventions in the firearms world, and it trips up beginners and experienced shooters alike.

Here’s the short answer: Glock model numbers are sequential patent and design numbers assigned by the company during development. They don’t tell you the caliber, the magazine capacity, or the frame size. The Glock 17 earned its name because it was founder Gaston Glock’s 17th patent — not because the magazine holds 17 rounds (though it does, by pure coincidence).

This numbering system has continued for over four decades, and every new design gets the next available number regardless of what caliber or size category it falls into. That’s why the Glock 45 is a 9mm pistol, the Glock 40 fires 10mm Auto, and the actual .22 LR Glock is the Glock 44. Once you accept that the numbers are essentially serial numbers for Glock’s engineering department, the whole system suddenly makes a lot more sense.

Why the Glock Numbering System Confuses Everyone

The biggest source of confusion comes from a handful of coincidences that make the numbering system look like it should mean something. The Glock 17 happens to hold 17 rounds, the Glock 21 shoots .45 ACP (close to “21” if you squint), and the Glock 22 was adopted by countless American police departments — leading people to assume the numbers carry significance.

But try applying any pattern and it falls apart immediately. If “17” meant magazine capacity, the Glock 19 should hold 19 rounds (it holds 15). If the numbers tracked caliber, the Glock 20 should fire .20-something (it fires 10mm Auto). And if higher numbers meant newer designs, the Glock 22 and 23 wouldn’t have been released before the Glock 20 and 21, even though the latter pair started development first.

The reality is that Glock assigns model numbers when a design project begins, not when the pistol ships. Some projects get shelved, some get fast-tracked, and the release order ends up looking random to anyone on the outside. It’s not a puzzle to solve — it’s just an internal filing system that became public-facing.

For the full deep-dive into every myth and misconception, check out our dedicated Glock Numbering System Explained article.

The Core Glock Model Families by Caliber

Rather than memorizing all 30+ model numbers, it helps to think of Glock’s lineup in terms of caliber families. Within each caliber, Glock follows a consistent sizing pattern: a full-size model, a compact, a subcompact, and sometimes a competition or slimline variant.

The 9mm family is by far the most popular and includes the Glock 17 (full-size), Glock 19 (compact), Glock 26 (subcompact), and Glock 34 (competition). Then there are the newer crossover models like the Glock 19X and Glock 45, which mix a full-size grip with a compact slide for shooters who want more to hold onto without the extra barrel length. The slimline 9mm options — the Glock 43, 43X, and 48 — were designed specifically for concealed carry, with single-stack or slim double-stack magazines that make the gun nearly disappear under a T-shirt.

The .40 S&W family mirrors the 9mm lineup almost exactly: the Glock 22 is full-size, the Glock 23 is compact, the Glock 27 is subcompact, and the Glock 35 is the competition variant. These were the standard-issue pistols for U.S. law enforcement for over two decades, though many agencies have since transitioned back to 9mm.

For shooters who want more power, the 10mm Auto family offers the Glock 20 (full-size), Glock 29 (subcompact), and Glock 40 (long slide competition). The Glock 20 has become a favorite for hikers and outdoorsmen who need serious stopping power for wildlife encounters. The .45 ACP family rounds things out with the Glock 21, Glock 30, Glock 36, and Glock 41, covering everything from full-size duty use to slim concealed carry.

There are also smaller families in .357 SIG (Glock 31, 32, 33), .45 GAP (Glock 37, 38, 39), .380 ACP (Glock 25, 28, 42), and .22 LR (Glock 44). The .380 and .22 models are excellent low-recoil training options, while the .357 SIG and .45 GAP models cater to more niche markets.

Understanding Glock Suffix Letters

Beyond the numbers, Glock uses letter suffixes that actually do tell you something useful about the gun:

The “L” suffix means long slide — the Glock 17L has a 6.02-inch barrel compared to the standard 4.49 inches, giving you a longer sight radius and higher muzzle velocity for precision work. The “C” stands for compensated, with ports cut into the barrel and slide that vent gas upward to reduce muzzle flip. If you’ve ever watched a competition shooter running a Glock that barely moves during rapid fire, there’s a good chance they’re shooting a C model or an aftermarket comp setup.

The most practically important suffix today is “MOS” — Modular Optic System. MOS models come with a slide pre-milled for red dot mounting, and if you’re getting into competitive shooting through IPSC Production Optics or just want a modern carry setup, the MOS is the way to go. The “X” suffix gets used in two different contexts: the Glock 19X is a crossover design (G17 frame, G19 slide), while the Glock 43X simply means an extended-grip version of the G43.

Other suffixes include SF (Short Frame, with a grip 3mm shorter for smaller hands), S (Slimline slide), and the now-discontinued MB (Magazine Button, for ambidextrous magazine release).

Glock Generations: From Gen 1 to the V Series

Every Glock generation brings meaningful improvements, and knowing which generation you’re looking at matters as much as the model number itself. The original Gen 1 (1982-1988) was only the Glock 17 — a smooth-grip polymer pistol that revolutionized the industry simply by proving that plastic-framed handguns could outperform steel ones in military trials.

Gen 2 (1988-1998) added grip texturing and expanded the lineup to multiple calibers. Gen 3 (1998-2010) introduced the finger grooves and accessory rail that became iconic Glock features. Gen 4 (2010-2017) brought interchangeable backstraps, a reversible magazine release, and a dual recoil spring — all addressing decades of user feedback about the one-size-fits-all grip.

Gen 5, launched in 2017, is the current standard for most models. It removed the finger grooves (which many shooters found more annoying than helpful), added a flared magwell for faster reloads, an ambidextrous slide stop, and the Glock Marksman Barrel (GMB) with improved polygonal rifling. For competition shooters, the Gen 5 barrel accuracy improvement alone makes it worth the upgrade.

In late 2025, the V Series introduced anti-conversion features and a redesigned slide cover plate to prevent illegal full-auto modifications. Then came the big one: Glock officially launched the Gen 6 lineup at SHOT Show in January 2026, marking the brand’s 40th anniversary of U.S. operations. The Gen 6 brings a redesigned frame geometry, a flat-faced trigger that feels noticeably crisper than the Gen 5’s hinged design, factory front slide serrations, and a new Gen 6 optic-ready system that makes mounting a red dot cleaner than ever.

Perhaps the most significant business move is that Glock has begun phasing out Gen 3 through Gen 5 production in favor of the Gen 6 and V Series. If you’re shopping for a new Glock in 2026, Gen 6 is the generation to buy — and if you find a Gen 5 at a discount, it’s still an excellent pistol that will serve you well for years.

For a detailed breakdown of every generation’s changes, see our Glock Generations Overview and the latest Glock Gen 6 Guide.

How to Pick the Right Glock for Your Purpose

Choosing a Glock becomes much simpler once you stop worrying about the number and focus on what you need the gun to do.

For competitive shooting, the Glock 34 is the go-to choice in both IPSC and IDPA circuits. Its longer barrel and sight radius give you an edge in accuracy without being unwieldy, and the competition-ready trigger is noticeably better than the standard models. If you’re shooting Production Optics division, the Glock 34 MOS or Glock 17 MOS are your best bets. Many serious competitors start with a Glock 17 Gen 5 because it’s the most widely supported platform for aftermarket upgrades — triggers, sights, magwells, you name it.

For everyday concealed carry, the Glock 19 remains the gold standard. It’s compact enough to carry inside the waistband without printing, yet large enough to shoot well at the range. If you need something even smaller, the Glock 43X offers a good balance between concealability and shootability with its 10-round slim magazine. The Glock 48 gives you a compact-length slide on a slimline frame — perfect if you want better sight radius without extra width.

For home defense, most instructors recommend the full-size Glock 17 or Glock 19. The larger grip and higher capacity give you every advantage when concealment isn’t a concern. And for outdoor use in bear or wildlife country, the Glock 20 in 10mm has earned a devoted following for its stopping power in a relatively lightweight package.

If you’re deciding between the two most popular models, our detailed Glock 19 vs Glock 17 Comparison breaks down exactly where each one shines.

Training with Your Glock

Owning the right Glock is only half the equation — consistent practice is what actually makes you faster and more accurate. Whether you’re training with a real firearm or an airsoft replica, a shot timer is essential for measuring your progress in draws, transitions, and reloads.

The AirsoftShotTimer app turns your phone into a training tool that works in your garage, living room, or backyard range. Pair it with dry fire practice using our Dry Fire Training Complete Guide and you can make real measurable improvements without spending a cent on ammunition.

For Glock-specific training programs, our Glock 17 Training Guide covers draw drills, accuracy fundamentals, and competition-ready skill progressions. And once your fundamentals are solid, work on your magazine reload techniques — a fast reload can save you a full second per stage in competition, which adds up to a massive advantage over a full match.

Frequently Asked Questions About Glock Models

What do the numbers on a Glock mean?

Glock model numbers are sequential patent and design numbers assigned internally during development. They don’t indicate caliber, capacity, or size. The Glock 17 was Gaston Glock’s 17th patent — the fact that its magazine also holds 17 rounds of 9mm is pure coincidence. Each new design gets the next available number, which is why the Glock 45 is a 9mm and the actual .22 LR model is the Glock 44.

The Glock 19 has been the best-selling Glock for years, and the new Gen 6 version launched in January 2026 continues that dominance. Its compact size works equally well for concealed carry, home defense, and range shooting. The Glock 17 is a close second, especially popular with competition shooters in IPSC and IDPA who want the longer sight radius.

How many Glock models are there?

Glock has produced over 50 distinct model numbers across six calibers (9mm, .40 S&W, .45 ACP, 10mm Auto, .357 SIG, .380 ACP, .45 GAP, and .22 LR). However, with the Gen 6 transition in 2026, Glock is streamlining its lineup and phasing out some lower-demand models, particularly in .40 S&W and .357 SIG.

Which Glock is best for beginners?

For most beginners, the Glock 19 is the ideal starting point. It’s compact enough to carry yet large enough to shoot comfortably, and the 9mm recoil is very manageable. If you’re specifically interested in competition shooting, step up to the Glock 17 or Glock 34 for the longer barrel and sight radius. Our Glock 17 Training Guide has structured drills to build your skills from day one.

What does MOS mean on a Glock?

MOS stands for Modular Optic System. Glock MOS models come with a pre-milled slide that accepts red dot sights without needing aftermarket machining. With the Gen 6’s improved optic-ready system, factory-mounted red dots sit lower and more securely than ever. If you’re getting into Production Optics competition or want a modern carry setup, MOS is the way to go.

Is Glock discontinuing older generations?

Yes. Starting in 2025-2026, Glock has been phasing out Gen 3 through Gen 5 production to focus on the Gen 6 and V Series. Existing Gen 5 pistols remain excellent firearms, and you may find them at reduced prices as dealers clear inventory. But for new purchases in 2026, the Gen 6 represents the latest in Glock’s engineering.

Further Reading