Complete Guide to Glock Models: From Long Slide to Subcompact

GLOCK handguns are probably the most popular handguns currently being made on planet Earth, and it’s easy to see why.

They’re ruggedly dependable, relatively cheap, and infinitely reliable.  There’s a reason that just about every US police force uses GLOCKS, and it’s the same reason why nearly every military on the planet fields them in one fashion or another.

They’re damn good guns.

There’s also over fifty different models, seven available calibers, multiple generations, and about a million and one aftermarket parts available.  So how do you choose?

Ultimately, there’s a GLOCK handgun for every need, whether you need a tiny pocket/backup gun that won’t let you down, or you need a full-size, fully customized race gun to go smoke the competition at your next IDPA meetup.

Glock Custom, Zev
Glock Custom, Zev Technologies

To help you pick the GLOCK that best suits your individual wants and needs, we put together this handy guide to help you separate the G21s from the G19s from the G43s to…well you get the idea.

Let’s get started.

GLOCK Generations

There are five generations of GLOCKS available, but the only ones you really need to worry about are the most recent three.

Gen 3, 4 and 5 GLOCKS are all excellent, and while the newest models do have some improved features, the design hasn’t changed all that radically across generations.  Take a look at the differences, see if they matter to you, and see if that’s worth it for your needs. A police trade-in Gen 3 might be half or even a third of the price of a new Gen 5 model.  

The main thing to be careful of here is the fact that parts and magazines may not work from one generation to another so be on the lookout when delving into customization or aftermarket mags.


GLOCK offers several of their pistols in an “SF” configuration.  This stands for “short frame” and indicates a model with a smaller grip circumference. These models are prized by women, young shooters, and men with smaller hands or shorter fingers.


GLOCK’s MOS system is basically just a fancy way of saying the guns come pre-milled to accept a red dot or holosight.  

Glock 19 with RMR
Glock 19 with RMR

If you’re looking at putting one of these on your guns anyway, see if you like the MOS design.

Glock 19 MOS

Glock 19 MOS


  • Faster aiming
  • Easy of use
  • Eliminates need for night sights


  • Requires batteries in the optic

It comes with a number of plates pre-drilled and tapped for common optics and it gives you the flexibility to swap optics easily.


9mm Luger or 9×19 or 9mm Parabellum is the most popular pistol round unless you count .22lr.  It’s used all over the world, by every Western military, and by just about every civilian gun owner.  If you’re only going to own one pistol, this is the caliber you should be looking at first in our opinion.


The G17 is the full-size workhorse of the GLOCK world and might be the most popular GLOCK just because of the number of police departments that use it as their duty gun.  

If you’re looking for a full-size, easy-to-shoot GLOCK, this is the one. It carries 17 rounds in the magazine plus one in the chamber.

GLOCK 19 and 19x

The G19 is the slightly cut-down version of the GLOCK 17.  It carries two fewer rounds in the magazine but trades those for easier concealability in a shorter grip and slide.  The G19 is the biggest challenger to the 17 in terms of sales volume and is one of the most popular carry guns on the planet.

Glock 19 - Gen 4

Glock 19 - Gen 4


  • Modular backstrap
  • Full Size

This is the standard by which all carry guns are judged.

The 19x is the new kid on the block and was created with tweaked and improved features to meet the needs of the US military’s MHS competition.  It comes in a factory FDE coating, and utilizes the easy-concealment of the G19’s frame, with the longer slide and increased sight radius to make the gun easier to shoot.  

Glock 19x

Glock 19x


  • Innovative configuration
  • Hugely popular among shooters and police departments

It is, according to some (including the author) in the top three choices for defensive handguns in the world.


The G26 is the subcompact double-stack 9×19 option.  It is designed to be a replacement for snub-nosed revolvers and other pocket guns while still offering 10+1 rounds on tap. The “baby GLOCK” is ideally suited for use as a backup gun as it will still accept magazines from larger double stack 9mm GLOCKS, but it can also serve as an easy-to-conceal primary weapon.


The G43 is the trimmer, slimmer, single-stack subcompact option in 9×19.  It holds 6+1 rounds of 9×19 goodness and is perfect for those who want to deep carry in a pocket or bag without worrying about printing.


The G34 is the long-slide competition 9×19 choice, and it is ideal for shooters who want that extra sight radius for additional accuracy.  It is difficult to conceal this gun, but it could work as an open carry option, but where it really shines is the field of competition. The G34 is the most common GLOCK seen in a competitive environment, and the model has brought home several national match trophies.


The G45 is the newest of the GLOCK models at the time of this writing and hasn’t actually been released yet.  It is a new model that takes styling notes from the 19x and uses a full-size grip to provide easy shooting.

Glock 45
Glock 45

Not much else is known about this model yet, and we will update this section upon release.

.40 Smith & Wesson GLOCKS

.40 S&W may be fading in popularity as a caliber, but it still has a loyal following who want to split the difference between 9mm and .45 ACP.  One of the big benefits of the .40 S&W GLOCK models is the ability to swap in a 9mm replacement barrel and use both calibers in the same gun.


The G22 is the full-size duty gun .40 S&W offering. The G22 is still one of the more popular duty guns used by law enforcement, though many are swapping to 9mm models. It holds 15+1 rounds.


The G23 is the same size as the G19 and is the compact, more concealable version of the G22. It has a capacity of 13+1.


The .40 S&W version of the baby GLOCK, the G27 offers .40 S&W power, in a subcompact package. It has a 10+1 capacity.


The long-slide G35 is the competition .40 S&W offering and is ideal for competitors who want a little bit more power than the 9mm brings.  Many competitors will swap in a 9mm barrel for training with the cheaper ammo.

Red Creek Custom Glock 35
Red Creek Tactical Custom Glock 35


.45 ACP is one of the most well-regarded handgun calibers in America.  This is what our grandfather’s carried in their sidearms in WWII. This is the quintessential American handgun cartridge.


The G21 is the full-size duty gun GLOCK in .45 ACP.  It is used by police and other law-enforcement agencies around the US and is a common sight among “Heavy Metal” 3Gun shooters, and backcountry bear hunters looking for a little backup. It has a capacity of 13+1.


The G30 is actually the subcompact version of the .45 ACP GLOCK.  It’s small size and large caliber make it a bit snappy under recoil, but for a deep carry gun, it serves perfectly well. It has a capacity of 10+1

Glock 30
Glock 30


The single-stack, subcompact .45 ACP GLOCK is a great option for those who want .45 ACP power, in the smallest form factor.  The 6+1 capacity is a bit less than your average 1911, but it conceals incredibly well and shoots at least as well as compared to larger .45 ACP handguns.


The G41 is another long slide, competition-oriented GLOCK, this time in .45 ACP.  It is especially popular with competitors looking to take advantage of power factor scoring mechanics, and it also makes for a truly amazing home defense gun. It has the same capacity as the G21 at 13+1


With improvements in hollowpoint technology, the popularity of the what was once considered to be the undersized .380 ACP has exploded.  With modern bullets offering increased damage to soft-targets, more and more people have been turning to .380 pocket guns for self-defense, so when GLOCK released their take on the .380 pocket gun, it sold like hotcakes.


The G42 is a single-stack, subcompact GLOCK chambered in .380.  It makes for an excellent backup gun or even a great deep-concealment gun.  

Glock 42

Glock 42


  • Unbeatable reliability
  • Huge aftermarket support
  • Consistent trigger


  • Glock trigger is never impressive
  • Higher cost out of the box than most pocket guns
  • Some people just don't like Glocks

Its small size allows it to quickly and easily disappear into a pocket or bag, but it the ergonomics and design still allow it to be surprisingly shootable. It has a capacity of 6+1.


10mm, often jokingly called “the best millimeter” is a common hunting and target shooting round loved for its flat trajectory and stopping power.  While some carry them for defense against human predators, the 10mm has a passionate following with hunters and wilderness guides in bear country who need a sufficiently powerful sidearm.


The G20 is the most popular sidearm in bear country, where you’ll see many hunters and outdoorsmen turning to rugged and dependable GLOCK platform to see them safe from North America’s largest predators.  

Glock 20

Glock 20


  • 15+1 capacity, massive for 10mm
  • Huge Glock aftermarket options

The G20 has a respectable 15+1 capacity.


For those who want 10mm power in a subcompact form factor, GLOCK makes the G29. Though a little hot to hold, the G29 is remarkably shootable and is perfect for anyone who needs a smaller, more compact 10mm sidearm.  It has a capacity of 10+1.


The long slide 10mm offering from GLOCK, the G40, is another common sight in bear country, but this one is also seen on the competition circuit among “Heavy Metal” competitors, and those looking to take advantage of power factor scoring. It has the same 15+1 capacity of the G20.

Glock 40

Glock 40


  • Configured for Glock Modular Optics System (optics sold separately)


.45 GAP is something of a niche cartridge and its hard to find on shelves, but it was developed by GLOCK to offer .45 ACP performance in pistols the size of comparable 9mm guns.  GLOCK currently has three .45 GAP models, the 37, 38, and 39 which are the full-size, compact, and subcompact models respectively. GLOCK has not yet brought forth GEN 5 versions of these models, and it’s unclear if they will.


.357 is another somewhat niche caliber.  The goal here, which was mostly met, was to have a smaller, autoloading pistol cartridge with the power of the venerable .357 Magnum that was so popular with law enforcement at the time of the rounds development.  GLOCK offers a full-size, compact, and subcompact pistol in this caliber, the 31, 32, and 33 respectively.

Custom Shops and Aftermarket Parts

While these GLOCK models are perfectly adequate from the factory, you can swap out triggers, slides, barrels, even the frame to make a GLOCK that is as much or as little of the original as you’d like.

If you’re looking for aftermarket magazines, our Best Glock Magazines has you covered. You might also want to look at upgrading your trigger since Glock’s have historically poor stock triggers. The Best Glock Triggers can help with that!

Final Thoughts

That does it for the various GLOCK models, generations, and configurations. Hopefully, if you were thinking about picking one up, or wanted an overview of the different options, this has been helpful.

Which of these GLOCKs do you want the most? Do you already own one? Which is your favorite? Let us hear from you in the comments below!

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2 years ago

Great article, thanks much for the information.

1 year ago

You forgot the Glock 25 in .380 Auto, once very popular here in Brazil, as 9mm, .40, .45 and others were “restricted” calibers. It has changed 3 years ago, now the 17 and 19 are the most selling Glocks.

Wayne Robinson
Wayne Robinson
1 year ago

Your article states you can change .40 cal Glocks (22, 23, 27, 35) to 9mm by swapping barrels. I think this is incorrect. You can change .40 cal to .357 SIG by swapping barrels.

Fact checker
Fact checker
1 year ago

Glock 19x has a 17 frame with a 19 slide. You got it reversed.

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