Glock

History

The company's founder and head engineer, Gaston Glock (1929–2023), had no experience in firearms design or manufacture when his first pistol, the Glock 17, was being prototyped. Glock had extensive experience in advanced synthetic polymers, which was instrumental in the company's design of the first commercially successful line of pistols with a polymer frame. Glock introduced ferritic nitrocarburizing into the firearms industry as an anticorrosion surface treatment for metal gun parts.

Development

In 1980, the Austrian Armed Forces announced that it would seek tenders for a new, modern duty pistol to replace their World War II–era Walther P38 handguns. The Federal Ministry of Defence of Austria formulated a list of 17 criteria for the new generation service pistol, including requirements that it would be self loading; fire the NATO-standard 9×19mm Parabellum round; the magazines would not require any means of assistance for loading; not be subject to accidental discharge from shock, strike, and drop from a height of 2 m (6 ft 7 in) onto a steel plate. After firing 15,000 rounds of standard ammunition, the pistol was to be inspected for wear. The pistol was to be then used to fire an overpressure test cartridge generating 5,000 bar (500 MPa; 73,000 psi). The normal maximum operating pressure (Pmax) for the 9 mm NATO is 2,520 bar (252 MPa; 36,500 psi).

Glock became aware of the Austrian Army's planned procurement, and in 1982, assembled a team of Europe's leading handgun experts from military, police, and civilian sport-shooting circles to define the most desirable characteristics in a combat pistol. Within three months, Glock had developed a working prototype that combined proven mechanisms and traits from previous pistol designs. In addition, the plan was to make extensive use of synthetic materials and modern manufacturing technologies, which led to the Glock 17 becoming a cost-effective candidate.

Several samples of the Glock 17 (so named corresponding to its magazine capacity or because it was the 17th patent procured by the company) were submitted for assessment trials in early 1982. After passing all of the exhaustive endurance and abuse tests, the Glock emerged as the winner. According to Friedrich Dechant, former head of the Austrian Armaments and Defence Technology Agency, the Glock P80 was clearly superior to other handguns in terms of performance, handling, charging capacity and price.

The handgun was adopted into service with the Austrian military and law enforcement in 1982 as the Pistole 80 (P80), with an initial order for 25,000 guns. The Glock 17 outperformed eight different pistols from five other established manufacturers (Heckler & Koch of Germany offered their P7M8, P7M13, and P9S, SIG Sauer of Switzerland bid with their P220 and P226 models, Beretta of Italy submitted their model 92SB-F, FN Herstal of Belgium proposed an updated variant of the Browning Hi-Power, and the Austrian Steyr Mannlicher entered the competition with the GB).

Product evolution

Glock has updated its basic design several times throughout its production history.

The first-generation (Gen 1) Glock pistols are most notably recognized by their smoother "pebble finish" grip and frame with no finger grooves. The Gen 1 frame pattern and design was used by Glock from 1982 through 1988 and pre-dates the checkered grip patterns used in the second generation of Glock pistols. The first Glock 17s imported to the US were serialized with an alphanumeric (two-letter prefix followed by three numbers) stamped into the slide, barrel, and a small metal plate inserted into the bottom side of the polymer frame. The first documented Glock 17s (by serial number) imported into the US were from the AF000 series in January 1986, followed by AH000, AK000, and AL000. These early Glock (Gen 1) pistols (serial number prefix AF through AM) were also manufactured with a barrel that had a smaller overall diameter and thinner bore walls, later known as "pencil barrels". The barrels were later redesigned with thicker bore walls, and manufacturing continued to evolve, improving the design of Glock pistols.

Many of the first-generation Glocks were shipped and sold in the iconic "Tupperware" style plastic boxes. The earliest Glock boxes had ammunition storage compartments that allowed for 17 rounds of 9mm to be stored with the pistol. Glock later changed this box design to meet BATF import requirements, and removed the ammunition storage compartments.

A mid-life upgrade to the Glock pistols involved adding checkering to the front strap and trigger guard, and adding checkering and serrations to the back strap. These versions, introduced in 1988, were informally referred to as "second-generation" or Gen2 models. However, Glock did not mark the pistols Gen2. In 1991, an integrated recoil spring assembly replaced the original two-piece recoil spring and tube design. The magazine was slightly modified, changing the floorplate and fitting the follower spring with a resistance insert at its base.

In 1998, the frame was further modified with an accessory rail (called the "Universal Glock rail") similar to a Picatinny rail to allow the mounting of laser sights, tactical lights, and other accessories. Thumb rests on both sides of the frame, and finger grooves were added to the front strap. Glock pistols with these upgrades are informally referred to as (early) "third-generation" models. Later third-generation models additionally featured a modified extractor that serves as a loaded chamber indicator, and the locking block was enlarged, along with the addition of an extra cross pin to aid the distribution of bolt thrust forces exerted by the locking block. This cross pin is known as the locking block pin and is located above the trigger pin.

Design details

Operating mechanism

The Glock 17 is a short recoil–operated, locked-breech semi-automatic pistol that uses a modified Browning cam-lock system adapted from the Hi-Power pistol. The firearm's locking mechanism uses a linkless, vertically tilting barrel with a rectangular breech that locks into the ejection port cut-out in the slide (the SIG Sauer system). During the recoil stroke, the barrel initially moves rearward, locked together with the slide about 3 mm (0.12 in), until the bullet leaves the barrel and the chamber pressure drops to a safe level. A ramped lug extension at the base of the barrel then interacts with a tapered locking block integrated into the frame, forcing the barrel down and unlocking it from the slide. This camming action terminates the barrel's movement while the slide continues back under recoil, extracting and ejecting the spent cartridge casing. The slide's uninterrupted rearward movement and counter-recoil cycle are characteristic of the Browning system.

Glock pistols incorporate several features intended to enhance reliability under adverse conditions, such as advanced metal coatings, "stub" slide guides instead of true frame rails, and an unusual cocking mechanism in which the trigger is partially responsible for cocking the striker. By relying partially on force from the shooter's trigger finger to cock the striker, a Glock effectively reduces the load on the recoil spring as the slide moves forward into battery. In contrast, almost all other striker-fired pistols on the market rely fully on the recoil spring to cock the striker.

Features

The slide features a spring-loaded claw extractor, and the stamped sheet metal ejector is pinned to the trigger mechanism housing. Pistols after 2002 have a reshaped extractor that serves as a loaded chamber indicator. When a cartridge is present in the chamber, a tactile metal edge protrudes slightly out immediately behind the ejection port on the right side of the slide. The striker firing mechanism has a spring-loaded firing pin that is cocked in two stages that the firing pin spring powers. The factory-standard firing pin spring is rated at 24 N (5.4 lbf), but by using a modified firing pin spring, it can be increased to 28 N (6.3 lbf) or to 31 N (7.0 lbf). When the pistol is charged, the firing pin is in the half-cock position. As the trigger is pulled, the firing pin is then fully cocked. At the end of its travel, the trigger bar is tilted downward by the connector, releasing the firing pin to fire the cartridge. The connector resets the trigger bar so that the firing pin will be captured in half-cock at the end of the firing cycle. This is known as a preset trigger mechanism, referred to by the manufacturer as the "Safe action" trigger. The connector ensures that the pistol can fire only semiautomatically.

The factory-standard, two-stage trigger has a trigger travel of 12.5 mm (0.49 in) and is rated at 25 N (5.6 lbf), but by using a modified connector, it can be increased to 35 N (7.9 lbf) or lowered to 20 N (4.5 lbf). In response to requests from American law enforcement agencies for a two-stage trigger with increased trigger pull, Glock introduced the NY1 (New York) trigger module, which features a flat spring in a plastic housing that replaces the trigger bar's standard coil spring. This trigger modification is available in two versions: NY1 and NY2 that are rated at 25 N (5.6 lbf) to 40 N (9.0 lbf) and 32 N (7.2 lbf) to 50 N (11.2 lbf), respectively, which require about 20 N (4.5 lbf) to 30 N (6.7 lbf) of force to disengage the safeties and another 10 N (2.2 lbf) to 20 N (4.5 lbf) in the second stage to fire a shot.

The Glock's frame, magazine body, and several other components are made from a high-strength nylon-based polymer invented by Gaston Glock, called Polymer 2. This plastic was specially formulated to provide increased durability and is more resilient than carbon steel and most steel alloys. Polymer 2 is resistant to shock, caustic liquids, and temperature extremes where traditional steel/alloy frames would warp and become brittle. The injection-molded frame contains four hardened steel guide rails for the slide: two at the rear of the frame, and the remaining pair above and in front of the trigger guard. The trigger guard itself is squared off at the front and checkered. The grip has an angle of 109° and a nonslip, stippled surface on the sides and both the front and rear straps. The frame houses the locking block, which is an investment casting that engages a 45° camming surface on the barrel's lower camming lug. It is retained in the frame by a steel axis pin that holds the trigger and slide catch. The trigger housing is held to the frame by means of a polymer pin. A spring-loaded sheet-metal pressing serves as the slide catch, secured against unintentional manipulation by a raised guard molded into the frame.

Barrel

The hammer-forged barrel has a female type polygonal rifling with a right-hand twist. The stabilization of the round is not by conventional rifling, using lands and grooves, but rather through a polygonal profile consisting of a series of six or eight interconnected noncircular segments (only the .45 ACP and .45 GAP have octagonal polygonal rifling). Each depressed segment within the interior of the barrel is the equivalent of a groove in a conventional barrel. Thus, the interior of the barrel consists of smooth arcs of steel rather than sharply defined slots. Instead of using a traditional broaching machine to cut the rifling into the bore, the hammer forging process involves beating a slowly rotating mandrel through the bore to obtain the hexagonal or octagonal shape. As a result, the barrel's thickness in the area of each groove is not compromised as with conventional square-cut barrels. This has the advantage of providing a better gas seal behind the projectile as the bore has a slightly smaller diameter, which translates into more efficient use of the combustion gases trapped behind the bullet, slightly greater (consistency in) muzzle velocities, and increased accuracy and ease of maintenance.

The newer lines of Glock pistols—i.e., Gen5, G42/43—are equipped with the Glock Marksmanship Barrel, or GMB. While older barrels were somewhat difficult to identify a bullet as coming from a particular barrel with high enough reliability for evidentiary use, the newer GMB ones are designed differently. A study by Stephen Christen and Hans Rudolf Jordi, published in Forensic Science International in February 2019, shows that the new GMB barrels leave more distinctive markings on the fired projectile. These marks were more easily identified than previous pistol barrel markings and were sufficient for reliably tying a bullet to a particular barrel. The study used a comparison microscope and an ABIS (Evofinder).

Safety

Glock pistols lack a traditional on-off safety lever, which Glock markets as an advantage, especially to police departments, as the user can fire immediately without separately manipulating a safety. Instead, the pistols are designed with three independent safety mechanisms to prevent accidental discharge. The system, designated "Safe Action" by Glock, consists of an external integrated trigger safety and two automatic internal safeties: a firing pin safety and a drop safety. The external safety is a small inner lever contained in the trigger. Pressing the lever activates the trigger bar and sheet metal connector. The firing pin safety is a solid, hardened steel pin that, in the secured state, blocks the firing pin channel (disabling the firing pin in its longitudinal axis). It is pushed upward to release the firing pin, firing only when the trigger is actuated and the safety is pushed up by the backward movement of the trigger bar. The drop safety guides the trigger bar in a ramp that is released only when direct rearward pressure is applied to the trigger. The three safety mechanisms are automatically disengaged one after the other when the trigger is squeezed, and are automatically reactivated when the trigger is released.

In 2003, Glock announced the Internal Locking System (ILS) safety feature named Glock Safety Lock. The ILS is a manually activated lock located in the back of the pistol's grip. It is cylindrical in design and, according to Glock, each key is unique. When activated, the lock causes a tab to protrude from the rear of the grip, providing both a visual and tactile indication of whether the lock is engaged. When activated, the ILS renders the Glock unfireable, as well as making it impossible to disassemble. When disengaged, the ILS adds no further safety mechanisms to the Glock pistol. The ILS is available as an option on most Glock pistols. Glock pistols cannot be retrofitted to accommodate the ILS. The lock must be factory-built in Austria and shipped as a special order.

Magazine

The Glock 17 feeds from staggered-column or double-stack magazines that have a 17-round capacity (which can be extended to 19 with an optional floor plate) or optional 24 or 33-round capacity magazines. For jurisdictions that restrict magazine capacity to 10 rounds, Glock offers single-stack, 10-round magazines. The magazines are made of steel and are overmolded with plastic. A steel spring drives a plastic follower. After the last cartridge has been fired, the slide remains open on the slide stop. The slide stop release lever is located on the left side of the frame directly beneath the slide and can be manipulated by the thumb of the right-handed shooter.

Glock magazines are interchangeable between models of the same caliber, meaning that a compact or subcompact pistol will accept magazines designed for the larger pistols chambered for the same round. However, magazines designed for compact and subcompact models will not function in larger pistols because they are not tall enough to reach the slide and magazine release. For example, the subcompact Glock 26 will accept magazines from both the full-size Glock 17 and the compact Glock 19, but the Glock 17 will not accept magazines from the smaller Glock 19 or the Glock 26. The magazines for the Glock 36, the Glock 42, the Glock 43, and the Glock 44 are all unique; they cannot use magazines intended for another model, nor can their magazines be used in other models.

Sights

The first Glock pistols sent to the United States in 1985 failed to meet the BATF import "points" requirement, requiring Glock to quickly develop an adjustable rear sight which allowed for the pistols to be imported and sold commercially in 1986. It is believed that Glock designed and created this adjustable rear sight over a weekend to meet the ATF's importation requirements, and so it was dubbed the "weekend" sight. These first-generation adjustable rear sights extended past the slide and were susceptible to breaking. Even on later models, the front sight can easily become misshapen from friction against the holster, leading to replacements with metal sights, or tritium illuminated night sights.

More commonly today, the Glock 17 has a fixed polymer combat-type sighting arrangement that consists of a ramped front sight and a notched rear sight with white contrast elements painted on for increased acquisition speed – a white dot on the front post and a rectangular border on the rear notch. Some newer rear sights can be adjusted for windage (on certain models, due to the windage sights not being included as a factory default), as they have a degree of lateral movement in the dovetail they are mounted in. Three other factory rear sight configurations are available in addition to the standard 6.5 mm (0.26 in) height sight: a lower impact 6.1 mm (0.24 in) sight, and two higher impact versions – 6.9 mm (0.27 in) and 7.3 mm (0.29 in).

Accessories

The Glock pistol accessories available from the factory include several devices for tactical illumination, such as a series of front rail-mounted "Glock tactical lights" featuring a white tactical light and an optional visible laser sight. An alternative version of the tactical light, using an invisible infrared light and a laser sight, is available and designed to be used with an infrared night vision device. Another lighting accessory is an adapter that mounts a flashlight to the bottom of a magazine.

Polymer holsters in various configurations and matching magazine pouches are available. In addition, Glock produces optional triggers, recoil springs, slide stops, magazine release levers, and maritime spring cups. Maritime spring cups are designed to allow the pistol to be fired immediately after being submerged in water. They feature additional openings that allow liquids to flow and escape around them, offering enhanced reliability when water has penetrated the firing pin assembly channel.

Magazine floor plates (or +2 baseplates), which expand the capacity of the standard magazines by two rounds, are available for models chambered for the 9×19mm Parabellum, .45 GAP, .40 S&W, .357 SIG, and .380 ACP cartridges. In addition to the standard nonadjustable polymer sight line, Glock offers three alternative sight lines. These consist of steel, adjustable, and self-illuminating tritium night rear sights and factory steel and self-illuminating tritium contrast pointer steel front sights.

The Glock 17 along with many variants can accept pistol conversion kits, with one such example being the FAB-Defense KPOS Scout. They can also accept special stocks like the Flux Defense Brace.

A Glock switch is an aftermarket accessory that depresses the firearm's sear, allowing fully automatic fire. Without the proper license, they are illegal in the United States.

Commemorative, anniversary, engraved, and other rare Glocks

Glock began producing limited edition and commemorative Glocks in 1991. Glock later produced a series of anniversary models to celebrate business milestones and in honor of 20, 25, and 30 years of US sales. Additionally, many law enforcement agencies had the department name, logo, or badges engraved on the slides of issued duty weapons.

Variants

Following the introduction of the Glock 17, numerous variants and versions have been offered. Different model numbers identify variants that differ in caliber, frame, and slide length, except for a few models with a letter suffix (the Glock 17L, 19X, 30S, and 43X).

The original double-stack "small frame" Glock pistols are made in five form factors, all modeled after the original full-sized Glock 17. "Standard" models are designed as full-sized duty firearms with a large magazine capacity. "Compact" models are slightly smaller with reduced magazine capacity and lighter weight while maintaining a usable grip length. "Subcompact" models are designed for easier carry and being lighter and shorter, are intended to be used with two fingers on the grip below the trigger guard, and lack an accessory rail like the larger, after generation two, Glock models. The other two form factors use the full-size "standard" frame with longer slides that include a lower section to fill in the space between the frame's dust cover and the front of the slide. The first of these is the "long slide" models, which were too long for certain IPSC classes, necessitating the creation of the intermediate "competition" models. Currently, the available chamberings for all five form factors are 9mm Parabellum (9×21mm in certain countries) and .40 Smith & Wesson. Additionally, .357 SIG and .45 GAP chamberings are offered in "standard", "compact", and "subcompact" models, while .380 ACP is offered only in "compact" and "sub-compact" models. Recently, so-called "crossover" versions in 9mm Parabellum pair short (front-to-back) "compact" frames with longer "standard" grip lengths. This was initially intended to provide a longer-grip, higher-capacity version of the Glock 19 (Glock 19X and Glock 45). Still, Glock developed the Glock 47 for US Customs and Border Protection, which used the G45 frame with a G17-length slide that included a front section to fill the gap between the dust cover and the front of the slide, a design that maintains the same overall dimensions as the Glock 17. Naturally, the next step was to couple this slide with the Glock 19 Frame, creating the Glock 49.

There are also the wider double-stack "large frame" Glock pistols for use with larger calibers, currently in 10mm Auto and .45 ACP. These models have bigger, wider slides and frames and are larger than the smaller-chambered pistols. These come in only "standard", "subcompact", "competition" (.45 ACP only), and "long slide" (10mm only). Additionally, Glock introduced the "subcompact" Glock 30S in .45 ACP, fitted with the Glock 36's slimmer, lighter slide. Also, in 2007, Glock introduced a "short frame" version of these large frame weapons to provide a grip better suited to small hands. The short frame was originally designed to compete in the now-canceled U.S. military Joint Combat Pistol trials for a new .45 ACP pistol to replace the M9 pistol. Glock's entry featured an optional ambidextrous magazine release and a MIL-STD-1913 rail, along with a reduced backstrap. The Glock 21SF was originally available in three versions: one with a Picatinny rail and an ambidextrous magazine release, and two with a Universal Glock rail, available with or without the ambidextrous magazine release. However, the ambidextrous release and Picatinny rail were soon dropped. As of January 2009, the Glock 20, 21, 29, and 30 were offered in short-framed variations. These models incorporate a 2.5 mm (0.098 in) reduction in trigger reach, and full-sized models feature a 4 mm (0.16 in) reduction in heel depth, which corresponds to an overall reduction in length for those models. The short frame models were not introduced for the Gen 4 and Gen 5 models, as the replaceable backstraps design makes a separate short frame version redundant.

9×19mm Parabellum

Glock 17: The Glock 17 is the original 9×19mm Parabellum model, with a standard magazine capacity of 17 rounds, introduced in 1982. Initial samples of the new civilian offering were marked Glock 82. But, it was decided not to use the year to designate civilian models, but to begin the model numbers at 17 and continue numerically from there. Glock also offers a version of the standard magazine that incorporates a longer "+2" base plate, increasing capacity to 19 rounds. Also, a 10-round version of the standard magazine was created for markets that restrict handgun magazine capacity. Glock also offers an extended 24-round (with flush base plate) magazine for the Glock 17. Finally, the Glock 17 can use the Glock 18's extended 33-round magazine (with a +2 base plate). The base plates for the extended magazines can be swapped out to create 26- and 31-round magazines as well. The longest-serving of the Glocks, the Glock 17 can be had with numerous "options," such as a threaded barrel or slides cut for the Modular Optic System (MOS). Some options, such as the universal Glock rail, have become standard. In addition, some features have been given their own suffixed model designations, creating entirely new models, all of which can use the same magazines as the Glock 17:

Glock 17L: Introduced in 1988, the 17L incorporates a longer slide and extended barrel. Initially, the Glock 17L had three holes in the top of the barrel and a corresponding slot in the slide; however, later production pistols lack these holes. The Glock 17L is manufactured in limited quantities.

Glock 17C: Introduced in 1996, the 17C incorporates slots cut in the barrel and slide to compensate for recoil. Many other Glock pistols now come with this option, all of which have a "C" suffix on the slide.

Glock 17MB: The 17MB is a version with an ambidextrous magazine catch. This model, along with the other MB variants, was no longer available when the fourth-generation models introduced a reversible magazine catch.

Glock 17M: Introduced in 2016, the 17M was created in response to an FBI solicitation for a new full-size 9mm pistol. Differences from the Generation 4 model include the removal of the finger grooves, an ambidextrous slide lock, a rounded slide nose profile, a flared magazine well with new magazine baseplates, and a tougher finish on metal components. The Glock 17M also abandons the polygonal rifling of previous models in favor of conventional rifling. As of 2017, the Federal Bureau of Investigation, the South Carolina Highway Patrol and the Ontario Provincial Police have adopted the pistol as standard.

9×21mm

The 9×21mm pistol cartridge was adopted and commercialized by Israel Military Industries for those markets (such as in France, Italy, and Mexico) where military service cartridges like the 9×19mm Parabellum are banned for civilian use. Glock produces 9×21mm-chambered versions of the Model 17, and other 9mm Parabellum models, for these markets. These alternative caliber versions are marked with the same model number as the 9mm Parabellum version only differing in the barrel and caliber marking. Glock does not export or produce the 9×21mm pistols for the United States commercial market. This makes any 9×21mm Glock model a unique and highly desirable item for US firearm collectors. A limited number of 9×21mm Glocks have found their way into the US and are mostly held by collectors and gun enthusiasts.

10mm Auto

Glock 20: The Glock 20, introduced in 1991, was developed for the then-growing law enforcement and security forces market for the 10mm Auto. The pistol handles both full-power and reduced "FBI" loads, which have lower muzzle velocity. Due to the longer cartridge and higher pressures, the pistol is slightly larger than the Glock 17, having a roughly 2.5 mm (0.1 in) greater width and 7 mm (0.3 in) greater length. Though many small parts interchange with the Glock 17, with a close to 50% parts commonality, the major assemblies are scaled-up and do not interchange. The standard magazine capacity of the Glock 20 is 15 rounds, and there are no other factory magazine offerings. In 2009, Glock announced that it would offer a 152 mm (6.0 in)-barrel as a drop-in option.

Glock 20SF: The 20SF is a version of the Glock 20 that uses the Short Frame (SF) which is based on the standard G20 frame (same width), but reduces the trigger reach from the back of the grip by 2.5 mm (0.098 in) and the heel of the pistol is shortened by 4 mm (0.16 in) so the trigger can be reached and operated better by users with relatively small hands.

Glock 29: The Glock 29 is a 10mm Auto equivalent of the subcompact Glock 26 introduced in 1997, along with the Glock 30 (.45 ACP). The pistol features a 96 mm (3.8 in) barrel and a standard magazine capacity of 10 rounds. Like other subcompact Glock pistols, the Glock 29 uses factory magazines from its full-size counterpart, offering an optional 15-round capacity.

Glock 29SF: The 29SF version of the Glock 29 uses the SF, which is based on the standard G29 frame (same width), but reduces the trigger reach from the back of the grip by 2.5 mm (0.098 in).

Glock 40: The Glock 40, introduced in 2015, is a 10mm Auto equivalent of the long-slide Glock 17L. The Glock 40 is only made with the "Gen4" frame and "MOS" (Modular Optic System) configuration. The Glock 40 uses the same magazine as the Glock 20.

.45 ACP

Glock pistols chambered for the .45 ACP (and the .45 GAP) feature octagonal polygonal rifling rather than the hexagonal-shaped bores used for models in most other chamberings. Octagonal rifling provides a better gas seal in relatively large diameter rifled bores, since an octagon resembles a circle more closely than a hexagon.

Glock 21: The Glock 21 is a .45 ACP version of the Glock 20 designed primarily for the American market. Compared to the Glock 20 chambered in 10mm Auto, the slide of the Glock 21 is lighter to compensate for the lower-energy .45 ACP cartridge. The standard Glock 21 magazine is of the single-position-feed, staggered-column type with a capacity of 13 rounds. While there is no other factory magazine, a "+1" base plate is available to make the magazine 14-round. The .45 ACP Glock 21 is capable of firing .45 Super ammunition.

Glock 21SF: The 21SF is a version of the Glock 21 that uses a Short Frame lower which is based on the standard G21 frame (same width), but reduces trigger reach from the back of the grip by 2.5 mm (0.098 in), and the heel of the pistol is shortened by 4 mm (0.16 in) so the trigger can be reached and operated better by users with smaller hands.

Glock 30: The Glock 30 is a .45 ACP version of the subcompact Glock 29, with a standard magazine capacity of 10 rounds. The standard magazine includes a "+1" base plate, and can be made into a 9-round magazine by swapping in a flush base plate. The factory magazine from the Glock 21, with a capacity of 13 rounds (14 rounds with the +1 base plate), will function in the Glock 30.

Glock 30SF: The 30SF is a version of the Glock 30 that uses a Short Frame lower, which is based on the standard G30 frame (same width), but reduces trigger reach from the back of the grip by 2.5 mm (0.098 in). The G30SF accepts the same double-stack .45ACP magazines as the G30 and G21.

Glock 30S: The 30S is a version of the Glock 30 that features a thin slide (same slide as the G36), a Short Frame lower, and the same double stack magazines as the Glock 30 and 21. Like the G30, G30S magazines holds 10 rounds.

Glock 36: The Glock 36 is a "slimline" version of the subcompact Glock 30 that features an ultracompact slide and frame and is chambered for the .45 ACP cartridge. The Glock 36 is the first Glock pistol to be manufactured with a single-stack magazine, having a standard capacity of six rounds and being unique to the model. The Glock 36 cannot use factory magazines from its larger relatives due to its single-stack magazine design.

.40 S&W

In 1990, Smith & Wesson and Winchester developed the .40 Smith & Wesson by shortening the 10mm case. This created a round that was more powerful than the 9mm Parabellum but with more manageable recoil. The round was also still operable in the smaller frame size used for Glock 9mm models. As is typical of many pistols chambered in .40 S&W, each of the standard Glock models (22, 23, and 27) may be easily converted to the corresponding .357 SIG chambering (Glock 31, 32, and 33, respectively) simply by replacing the barrel. No other parts need to be replaced, as the .40 S&W magazines will feed the .357 SIG rounds.

Glock 22: The Glock 22 is a .40 S&W version of the full-sized Glock 17 introduced in 1990. The pistol uses a modified slide, frame, and barrel to accommodate the differences in size and power between the .40 S&W cartridge. The standard magazine capacity is 15 rounds. A 10-round version of this magazine is also offered for those markets where the magazine capacity for handguns is restricted. Additionally, the standard magazine is available with a "+1" base plate to make it a 16-round magazine. And, there is a Glock factory 22-round extended magazine offered. One can also swap in the +1 base plate to make that a 23-round magazine. The Glock Model 22 is favored and used by multiple law enforcement agencies around the world, including the Baltimore Police Department, Los Angeles Police Department, Miami Police Department, Maryland State Police, Cumberland County Sheriff's Department (NJ), Overland Park Police Department, Kansas City Police Department, Missouri State Highway Patrol, and Alaska State Troopers in the United States; the NSW Police Force, Queensland Police Service, Western Australia Police Force, and the Northern Territory Police Force in Australia; the Edmonton Police Service, Calgary Police Service, Alberta Sheriffs Branch, Winnipeg Police Service, Toronto Police Service, Ottawa Police Service, and British Columbia Sheriff Service in Canada; and the National Bureau of Investigation (Philippines).

Glock 23: The Glock 23 is a .40 S&W version of the compact Glock 19. It is dimensionally identical to the Glock 19 but is slightly heavier and uses a modified slide, frame, and a .40 S&W barrel, with a standard magazine capacity of 13 rounds. For jurisdictions that limit handgun magazine capacity, Glock also offers a 10-round version of the standard magazine. There is also a factory 14-round version of the standard magazine using the +1 base plate. Finally, any magazine made for the Glock 22 will work in the Glock 23.

Glock 23C: Introduced in 1998 as part of the Generation 3 production series. This Glock 23 variant comes from the factory with two ports cut in the barrel and corresponding slide cuts. This allows gases to be ported upwards on firing, providing downward force on the muzzle. They were not as popular with law enforcement agencies as the standard 23C, but were utilised by the Fulton County Sheriff's Department, of Georgia, United States.

.380 ACP

The first two .380 ACP models (Glock 25 and 28) were released in 1995 to provide a less powerful alternative to the 9mm Parabellum and 9×21mm, primarily intended for markets such as Brazil that prohibit civilian ownership of firearms chambered in more powerful calibers. Made in Austria, import restrictions ban civilian importation into the United States, but a limited Glock 28 run was manufactured in Glock's US plant for US sale. The Glock 25 and 28 are banned in Canada as they do not meet the minimum handgun barrel length requirements.

Due to the relatively low bolt thrust of the .380 ACP cartridge, the locked-breech design of the Glock 19 and Glock 26 was minimally modified for the Glock 25 and Glock 28 to implement unlocked breech operation. It operates via straight blowback of the slide. This required modifying the locking surfaces on the barrel and redesigning the former locking block. Unusual for a blowback design, the barrel is not fixed to the frame. It moves rearward in recoil until it is tilted below the slide, similar to the standard locked-breech system. The reduced size and mass of the Glock 42 allowed the return to the Glock-standard locked-breech design.

Glock 25: The Glock 25 , introduced in 1995, is a blowback derivative of the compact (102 mm (4.0 in) barrel) Glock 19. The magazine capacity is 15 rounds. Standard fixed sight elevation is 6.9 mm, unlike the 6.5 mm elevation used for the 9×19mm models.

Glock 28: The Glock 28 , introduced in 1997, is a blowback derivative of the subcompact (87 mm (3.4 in) barrel) Glock 26. The standard magazine capacity is 10 rounds, but the 15-round Glock 25 magazine will function in the Glock 28. Standard fixed-sight elevation is 6.9 mm, unlike the 6.5 mm elevation used for the 9×19mm Parabellum models.

Glock 42: The Glock 42 , introduced in 2014, is a locked-breech "slimline" (83 mm (3.3 in) barrel) design, the smallest model Glock made. The single-stack magazine holds six rounds. US-manufactured Glock 42s may be sold for civilian use in the US.

.357 SIG

In 1994, SIG and Federal developed the .357 SIG to match the ballistics of typical .357 Magnum loads. This was done by necking down a shortened 10mm case to .357, which made it easy for Glock to alter their .40 Smith & Wesson models to the new caliber. As is typical of pistols chambered in .357 SIG, each of the standard Glock models (31, 32, and 33) may be easily converted to the corresponding .40 S&W chambering (Glock 22, 23, and 27, respectively) simply by replacing the barrel. The .357 SIG magazines differ from the .40 S&W counterpart by adding an internal rib on each side of the magazine body, with cutouts for the follower. This guides the bottlenecked cartridges through the feeding process. While it is possible to load .40 S&W into these magazines, the friction causes the larger rounds to lock up inside the magazine body, which can induce malfunctions. .40 S&W magazines do not have this feature and can load both .357 SIG and .40 S&W respectively.

Glock 31: The Glock 31 is a .357 SIG variant of the full-sized Glock 22. The standard magazine capacity of the Glock 31 is 15 rounds. It can also accept magazines intended for the Glock 22.

Glock 32: The Glock 32 is a .357 SIG variant of the compact Glock 23. The standard magazine capacity of the Glock 32 is 13 rounds. It can also accept magazines intended for the Glock 31, Glock 22, or Glock 23.

Glock 33: The Glock 33 is a .357 SIG variant of the subcompact Glock 27. The standard magazine capacity of the Glock 33 is 9 rounds. It can also accept magazines intended for the Glock 32, Glock 31, Glock 22, Glock 23, and Glock 27.

.45 GAP

Glock pistols chambered for the .45 GAP (and the .45 ACP) feature octagonal polygonal rifling rather than the hexagonal-shaped bores used for models in most other chamberings. Octagonal rifling provides a better gas seal in relatively large diameter rifled bores, since an octagon will have shorter sides and shallower angles than a hexagon.

Glock 37: The Glock 37 is a .45 GAP version of the Glock 17. It uses a wider, beveled slide, a larger barrel, and a different magazine, but is otherwise similar to the Glock 17. The Glock 37 first appeared in 2003. It was designed to offer ballistic performance comparable with the .45 ACP in the frame size of the Glock 17. The concern with the size of the Glock 20/21 has been addressed by the Glock 36, 21SF, and 30SF, all of which feature reduced-size frames. The standard magazine capacity of the Glock 37 is 10 rounds.

Glock 38: The Glock 38 is a .45 GAP version of the compact Glock 19. The standard magazine capacity of the Glock 38 is 8 rounds, but it can use the 10-round magazines of the Glock 37.

Glock 39: The Glock 39 is a .45 GAP version of the subcompact Glock 26. The standard magazine capacity of the Glock 39 is 6 rounds, but it can use the 8- and 10-round magazines of the Glock 37 and Glock 38.

.22 Long Rifle

Glock 44: The Glock 44 is a .22 Long Rifle rimfire model based on the Glock 19. While the Glock 44 is similar in size to the Glock 19, it has a magazine capacity of 10 rounds and uses a simple blowback mechanism rather than the locked-breech mechanism used on nearly all other Glock pistols. The Glock 44 is lighter than the G19 at 12 ounces. It retains Glock's polygonal rifling, which Glock has tested to work with lead .22 bullets. It uses a steel/polymer composite slide due to the lower slide mass required to function with the less powerful cartridge. The 44 uses the company's proprietary "Safe Action" trigger, and of a footprint such that holsters made for the 19 or 23 are interchangeable with the 44.

Production in other countries

Russia: Russian firms such as Skat, ORSIS, and Izhmash assemble three models of Glock pistols locally: the Glock 17, 34, and 35. Efforts to have Glocks made in Russia started from 2012.

Uruguay: As of 2015, there were plans to assemble Glock 17 pistols at army workshops in Uruguay to fulfill the needs of the national military services and law enforcement organizations.

United States: Glock pistols are manufactured by the Glock Inc. subsidiary division located in the United States. Those batches are identical to the Austrian-made ones, but they are marked as "USA", instead of "AUSTRIA", on the slide.

Clones

Third-party frames and slides for Glock pistols began to appear in the early 2000s. This has led to "Glock" becoming a generic term, including pistols not made by Glock GmbH, especially as expiring patents allowed complete Glock clones to be made. Many American companies produce Glock clones.

China: In 2017, it was reported that Norinco was able to make a clone of the Glock 17 known as the NP-7 (or NP7). The pistol was subcontracted to Hunan Ordnance Industry Group through the Hunan Ordnance and Light Weapons Research Institute. Its features appear to be influenced by the fourth-generation Glock 17. The NP7 is marketed for export.

Iran: Three unlicensed clones of Glock pistols made by Iranian DIO's Shahid Kaveh Industry Complex are named Ra'ad (with a safety selector, possibly an unlicensed copy of Glock 17), Glock 19 and Kaveh-17 (probably an improved Ra'ad, a variant of Glock 17S). It is not known if they could be adopted by the Iranian military to replace Browning Hi-Power, M1911 and SIG P226 pistols, and they were possibly prototypes that did not proceed to mass production.

Myanmar: The Tatmadaw have adopted a clone of the Glock 17 known as the MA5 MK II, first reported in 2018. As of 2019 they were being manufactured for Myanmar's special forces units. The pistol has a rounded trigger guard and the Tatmadaw emblem on the grip, which has rectangular spacing instead of the smaller dot-like spacing.

Pakistan: Unlicensed Glock clones are made in Pakistan's Khyber region, which were first reported in 2018.

Taiwan: The 205th Arsenal in Taiwan produces a copy of the Glock 19, named the T97 pistol. The Taiwan-made Glocks were made to replace the Smith & Wesson Model 5906 used by the Taiwan police, but it ultimately did not enter service.

Turkey: Akdal Arms produces a pistol named the Ghost TR01, which is heavily influenced by Glock pistols in its design.

United States: Ruger produces the RXM, which uses a Glock Gen 3 compatible grip module paired with a serialized fire control unit similar in concept to the SIG Sauer P320.

Criminal use

Glock pistols have been used in numerous high-profile criminal incidents in the United States. Mass shootings involving Glock pistols include the 1991 Luby's shooting, the 2007 Virginia Tech shooting, the 2011 Tucson shooting, the 2012 Aurora theater shooting, the 2012 Sandy Hook Elementary School shooting, the 2015 Charleston church shooting, the 2016 Pulse nightclub shooting, the 2018 Pittsburgh synagogue shooting, and the 2022 New York City Subway attack. Notable single-victim killings include the 1996 murder of Tupac Shakur. In February 2020, stuntwoman Cheryl Wheeler-Dixon and her husband Robert Reed Sanders were killed with a Glock pistol by her ex-husband in Yellow Springs, Ohio, in an incident where both sides were armed with Glocks; a grand jury determined the shooting was a justifiable homicide after investigators found evidence the couple had driven from North Carolina intending to murder him. In June 2022, Ilene Steur, a survivor of the 2022 NYC subway attack, sued Glock and its Austrian parent company for compensation for her physical injuries and emotional pain.

Glock pistols have also been used in mass shootings elsewhere in the world, including the 2001 Nepalese royal massacre, the 2002 Erfurt massacre, the 2002 Nanterre massacre, the killings committed by Viktor Kalivoda in 2005, the 2011 Norway attacks, the 2012 Bucharest hair salon shooting, the 2016 Munich shooting, the 2023 Rotterdam shootings, the 2023 Prague shootings and the 2025 Graz school shooting.

A 2014 report by the Chicago Police Department found that Glock pistols were the third most traced handgun, coming after those from Smith & Wesson and Sturm, Ruger & Co. Experts on gun control, mass shootings, and defense training have cited factors such as reliability, ease of use, and commonness for why Glock pistols are so often involved in mass shootings and other criminal acts. The criminal use of handguns, including Glocks, has led to calls for increased gun control in the United States. This common usage, however, has been described by Paul M. Barrett to be a result of Glock's overall popularity and market presence in the US and that "this level of violence isn't necessarily tied to a particular[,] to a brand".

Glock pistols were singled out for restriction by some jurisdictions. They were branded the "hijacker's special" based on the false assumption that they could bypass airport metal detectors because of their polymer frame. This was refuted in Congressional hearings by the ATF, FAA, and other organizations responsible for airline security, which proved embarrassing for the ban's advocates and provided significant publicity for Glock.