If I graded the way different companies named their guns, Glock might get an F. All they use is a number without any other identifying information. Sometimes they might add a letter or initial to the end of the number to make things a little trickier.
You have to be a real nerd to be able to decode the Glock naming systems. Luckily for you, I’m a giant gun nerd, so let’s dig into and decode the Glock designations.
Glock Model Numbers
Glock model numbers start with 17 and go up. The numbers do not correlate with caliber, frame size, or design in any way. It’s essentially just a numbered list of guns in the order they were produced and released.
The first Glock handgun, the Glock 17, was Gaston Glock’s 17th patent, and since then, the guns have been designated as numbers. So, the Glock 40 isn’t a .40 S&W, it’s a 10mm. The Glock 44 is actually a .22LR, and the Glock 45 is a 9mm.
It can be a bit confusing, especially if you ask for a Glock 45 and get handed the .45 ACP Glock 21. The first thing we’ll break down in this article is the various Glock designations, by caliber.
Glock Handguns, By Caliber
.22 LR Glock
Glock 44: Glock’s only .22LR is a straight blowback design with a compact size.
Glock 25: This model has a straight blowback design with a double-stack 15-round magazine in a compact frame size.
Glock 28: The G28 has a straight blowback design with a double-stack magazine in a subcompact frame size.
Glock 42: This model has a locked breech short recoil design with a single stack magazine in a Slimline frame size.
.357 SIG Models
Glock 31: This is a full-sized handgun with a double-stack 15-round magazine.
Glock 32: The G32 is a compact with a double-stack, 13-round magazine.
Glock 33: This model is a subcompact with a double stack 9-round magazine.
Glock 17: The Glock 17 is a full-sized handgun with a double-stack 17-round magazine.
Glock 17L: The first Glock with a long slide and barrel, the G17L uses a Glock 17 frame with 17-round double-stack magazines.
Glock 18: This one is full size, with double stack 17 to 33-round magazine. It’s a selective fire machine pistol.
Glock 19: The G19 is a compact with a double-stack, 15-round magazine.
Glock 19X: This model has a full-sized frame with a compact slide and a double stack, 17-round magazine. This pistol was designed for the MHS contract. It has a lanyard loop and a front lip on the magazine well. It cannot use GEN 5 magazines and domes in coyote color only.
Glock 26: This is a subcompact with a double-stack, 10-round magazine.
Glock 34: The G34 is a competition model with a longer barrel and full-sized frame with a double stack, 17-round magazine. Its barrel and slide are slightly shorter than 17L.
Glock 43: This is a Slimline model with six-round, single-stack magazine.
Glock 43X: A Slimline model with G43 slide and G48 frame and single stack 10-round magazine.
Glock 45: This model has a full-sized frame with a compact slide with a double stack, 17-round magazine.
Glock 46: The G46 has a compact frame with a double stack, 15-round magazine. It uses a rotary barrel breech design.
Glock 47: This is a full-sized handgun, with double stack 17-round magazine. It has greater parts commonality with the Glock 19, allowing the G47 barrel and slide to mount to a Glock 19 frame and the Glock 19 barrel and slide to mount to a Glock 47 frame.
Glock 48: This model has a Slimline frame with single stack 10-round magazine.
Glock 49: The G49 has a full-length slide mated to a compact frame, with double stack 15-round magazine.
.40 &SW Models
Glock 22: This is a full-sized handgun, with a double stack 15-round magazine.
Glock 23: The G23 is a compact model with a double-stack, 13-round magazine.
Glock 27: This is a subcompact model with a double stack 9-round magazine.
Glock 24: The Glock 24 has a competition-length slide with a full-size frame and double stack 15-round magazine.
Glock 35: This model also has a competition length slide with a full-size frame and double stack 15-round magazine. The barrel is slightly shorter than the Glock 24.
.45 ACP Models
Glock 21: The G21 has a full-size design with a double stack 13-round magazine.
Glock 30: This model has a subcompact design with a double-stack 9-round magazine.
Glock 36: The Glock 36 has a Slimline design with a single stack 6-round magazine.
Glock 41: The G41 has a competition-length slide with a full-sized frame and a double-stack 13-round magazine.
.45 GAP Models
Glock 37: This model has a full-sized design with a double-stack 10-round magazine.
Glock 38: The G38 has a compact design with a double-stack, 8-round magazine.
Glock 39:- The Glock 39 has a subcompact design with a double-stack 6-round magazine.
Glock 20: The Glock 20 has a full-size design with a double-stack 15-round magazine.
Glock 29: This model has a subcompact design with a double-stack 10-round magazine.
Glock 40: The G40 has a competition-length slide with a full-sized frame and double stack 15-round magazine.
Outside of the various calibers that Glock handguns are chambered in, you’ve probably seen various frame and slide sizes mentioned. Let’s briefly decode this part of the Glock designations system.
Full-sized Glocks feature a full-length grip module with a height of approximately 5.5 inches and a barrel length of 4.5 inches. This is an approximation and will vary based on caliber. Full-sized guns like the Glock 17 are typically duty or home defense guns.
Compact Glocks have a reduced-length grip with a height of approximately 5 inches and a barrel length of around 4 inches. This is an approximation and will vary based on caliber. Compact Glocks like the Glock 19 can be used for concealed carry, home defense, and duty use.
Subcompact Glocks are typically the smallest double-stack Glock models. Their height is around 4.15 inches, and their barrel lengths tend to be about 3.43 inches long. This is an approximation and will vary based on caliber. Subcompact Glocks tend to be used for concealed carry or as backup guns.
Long slide models have full-sized frames but sport longer barrels and slides. The modern long slide barrels can vary from roughly 5.31 inches to 6 inches, depending on the model. Long slides are often used for competition, but models like the Glock 40 are capable of medium-game hunting handguns.
Large frame refers to the frame utilized for the double stack 10mm and 45 ACP options. These platforms use a larger frame than the standard 9mm, .40 S&W, .357 SIG, and .45 GAP guns. The 10mm and .45 ACP have longer overall cartridge lengths, which necessitate the larger frames.
Slimeline refers to Glock single-stack guns. These guns tend to be aimed at concealed carry and come in numerous grip and slide lengths.
Hybrid frames use a combination of different frame sizes and slide lengths. Some use compact slides with full-sized frames, like the G45. Others use compact frames and full-length slides like the G49. There are also hybrids of the slimline design with the G43X.
Other Glock Models
You may see Glock designations followed by specific letters. There are lots of companies who produce custom Glocks, Glock parts, 80 lower receivers, and much more, but we’ll stick to Glock OEM guns. These letters refer to specific features of that model. Let’s break those down so we have a better understanding of the design.
SF stands for short frame. Short frame guns are large frame .45 ACP and 10mm guns that have had the reach to trigger reduced by 2.5mms to accommodate smaller-handed shooters.
MOS stands for Modular Optics System and is Glock’s factory red dot system. It uses a series of plates to allow for over a dozen different optics to be mounted to the slide.
C stands for Compensated, and the barrel and slide feature compensator cuts to reduce the upward rise of the gun while firing.
MB means that it’s a Gen 3 Glock with an ambidextrous magazine catch. These were discontinued when the Gen 4 was introduced.
The Glock Generations
Another core part of a Glock’s identity is which generation it belongs to. Glock currently has five main generations. They are often mentioned alongside the Glock designations, so they are an important part of the gun’s identity.
Gen 1 guns were produced from 1982 through 1986, and are collector’s items these days. They are known for their pebble-like grip texture, and some early models feature very thin barrels, which are highly collectible.
Gen 2 guns added checkering to the front strap, checkering and serrations to the back strap, and serrations to the trigger guard. To meet ATF regulations, a steel plate with the serial number was stamped into the frame. Slight modifications were also made to the magazine and recoil spring assembly.
Gen 3 guns were introduced in 1998 and might be the most famous. These guns added the beloved rail and the much-maligned finger grooves. Thumb rests were added to both sides of the frame as well. A modified extractor that served as a loaded chamber indicator was added. Glock enlarged the locking block and added an extra cross pin to aid in distributing bolt thrust force exerted by the locking block.
Gen 4 guns were introduced in 2010, with several ergonomic changes. This includes a more aggressive grip texture and interchangeable backstraps, and the basic grip is slightly reduced. Magazine catches were enlarged, and they could be reversed for left-handed shooters. A dual recoil spring assembly was added to help reduce recoil. Glock resized the slide and barrel shelf, with the front portion being wider and enlarged for the dual recoil spring assembly.
Gen 5 guns were introduced in 2017. They eliminated the finger grooves, utilized ambidextrous slide locks, and added a flared magwell. Glock also produced the Glock Marksman Barrel, a new barrel with a deeper recessed crown, which is supposed to aid in accuracy. Front slide serrations were added, and a DLC finish was applied to the slide and barrel.
The World of Glock
An endless array of numbers certainly doesn’t help in making one gun easier to decipher than another. Hopefully, we’ve helped you decode Glock designations.