The Glock pistol, sometimes referred to by the manufacturer as a Glock “Safe Action” Pistol or colloquially as a Glock, is a series of polymer-framed, short recoil-operated, locked breech semi-automatic pistols designed and produced by Glock Ges.m.b.H., located in Deutsch-Wagram, Austria. It entered Austrian military and police service by 1982 after it was the top performer on an exhaustive series of reliability and safety tests.

Despite initial resistance from the market to accept a “plastic gun” due to durability and reliability concerns, and fears–subsequently shown to be unfounded–that the pistol would be “invisible” to metal detectors in airports, Glock pistols have become the company’s most profitable line of products, commanding 65% of the market share of handguns for United States law enforcement agencies, as well as supplying numerous national armed forces, security agencies, and police forces worldwide.

Glocks are also popular firearms among civilians for recreational/competition shooting, home/self defense, and concealed or open carry.

Operating mechanism

The Glock 17 is a 9 mmP, 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. During the recoil stroke, the barrel moves rearward initially locked together with the slide about 3 mm (0.12 in) until the bullet leaves the barrel and 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.

Features /Components

A subcompact Glock 30 field stripped to its main parts with a .45 ACP round

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 as the “Safe Action” trigger by the manufacturer. The connector ensures the pistol can only fire semi automatically.

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 a request made by 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 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, which is secured from unintentional manipulation by a raised guard molded into the frame.

The Glock pistol has a relatively low slide profile, which holds the barrel axis close to the shooter’s hand and makes the pistol more comfortable to fire by reducing muzzle rise and allows for faster aim recovery in rapid firing sequences. The rectangular slide is milled from a single block of ordnance-grade steel using CNC machinery. The barrel and slide undergo two hardening processes prior to treatment with a proprietary nitriding process called Tenifer. The Tenifer treatment is applied in a 500 °C (932 °F) nitrate bath. The Tenifer finish is between 0.04 and 0.05 mm (0.0016 and 0.0020 in) in thickness, and is characterized by extreme resistance to wear and corrosion; it penetrates the metal, and treated parts have similar properties even below the surface to a certain depth.

The Tenifer process produces a matte gray-colored, non-glare surface with a 64 Rockwell C hardness rating and a 99% resistance to salt water corrosion (which meets or exceeds stainless steel specifications), making the Glock particularly suitable for individuals carrying the pistol concealed as the highly chloride-resistant finish allows the pistol to better endure the effects of perspiration. Glock steel parts using the Tenifer treatment are more corrosion-resistant than analogous gun parts having other finishes or treatments, including Teflon, bluing, hard chrome plating, or phosphates. After applying the Tenifer process, a black Parkerized decorative surface finish is applied. The under laying Tenifer treatment will remain, protecting these parts even if the decorative surface finish were to wear off.

A current production Glock 17 consists of 34 parts. For maintenance, the pistol disassembles into five main groups: the barrel, slide, frame, magazine, and recoil-spring assembly. The firearm is designed for the NATO-standard 9×19mm Parabellum pistol cartridge, but can use high-power (increased pressure) +P and +P+ ammunition with either full-metal-jacket or jacketed hollow-point projectiles.

Barrel

Standard sighting arrangement of a “first-generation” Glock 17

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.

The method by which Glock barrels are rifled is somewhat unusual; instead of using a traditional broaching machine to cut the rifling into the bore, the Glock 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 around 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 Safety

Glock pistols are designed with (3) 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 for firing only when the trigger is actuated and the safety is pushed up through 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. This passive safety system omits the manipulation of traditional on-off levers, hammers, or other external safeties as found in many other handgun designs.

In 2003, Glock announced the Internal Locking System (ILS) safety feature. 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, giving both a visual and tactile indication as to whether the lock is engaged or not. 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.

Feeding the rounds

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 33-round high-capacity magazines. For jurisdictions which restrict magazine capacity to 10 rounds, Glock offers single-stack, 10-round magazines. The magazines are made of steel and are over molded 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, and the Glock 43 are all unique; they cannot use magazines intended for another model, nor can their magazines be used in other models.

Some of the information on this page was sourced from Wikipedia