GLOCK 17

HISTORY

The Glock 17, designed by Gaston Glock, was adopted by the Austrian Army as its service pis-tol in 1982. As an Austrian engineer with no prior firearms design experience, this was Glock’s first firearm design. Some of his previous projects included curtain rods, shovels, and hand gre-nades. The Glock 17 is named not because of its 17-round magazine capacity, but because it was Gaston Glock’s 17th patent.

Glock pistols were first imported into the United States in 1988. Since then, there have been many variations and generations of the Glock, but all share the same basic design elements. All Glock models and generations operate in exactly the same manner. Since its introduction, the Glock pistol has come to dominate the United States handgun market. Over 75% of U.S. law enforcement agencies now use Glock pistols.

SAFETYThe Glock “Safe Action”® System has no external levers to manipulate in order to make them “safe” or “ready to fire.” The action is never fully cocked except when the trigger is pulled completely to the rear. All Glock pistols have

three automatic internal safeties that work sequentially off of the movement of the trigger. The first safety is the trigger safety, which is designed to block any unwanted rearward movement of the trigger due to inertia or lateral pressure. The firing pin safety blocks any unwanted forward movement of the firing pin that might have happened due to inertia or premature sep-aration of the firing pin and trigger bar. The drop safety prevents any premature disen-gagement of the trigger bar and the firing pin by not allowing the back of the trigger bar to move downward unless the trigger is pressed. As the trigger is intentionally pressed to the rear, the safeties are re-leased one by one until the pistol fires and the trigger is released forward. After firing, the safeties re-engage fully in sequence. This process takes place for each and every time the trigger is pressed to the rear.

DESIGN Glock pistols are the product of advanced technology and incorporate numerous innovative design features, which result in ease of operation, extreme reliability, simple function, minimal maintenance, durability, and light weight. Glock was the first company to mass produce a polymer handgun receiver and marry it to a steel slide and barrel. Glock pistols combine the safety and simplicity of revolver-like opera-tion with a manageable constant double-action-only trigger pull. In addition to these features, the Glock also has the benefit of a high magazine capacity and the reduced recoil of a modern semi-automatic pistol. This reduced felt recoil is due in large part to the low barrel axis of the design and the recoil absorbing benefits that come with a polymer frame.

One of the prominent design features is the lack of a traditional “hammer.” Glock pistols use a firing system known as “striker” fire. A spring-loaded striker is pulled to the rear mechanically until is it released under spring pressure to strike the primer of the cartridge. In a traditional style hammer-fired pistol, the hammer is drawn back mechanically until released under spring pres-sure. The hammer then falls onto the firing pin, which in turn fires the cartridge. The benefits of a striker-fired pistol are less internal parts, constant trigger pull (the same weight with every pull of the trigger), and a lower bore axis. The drawback of a striker-fired system is that it does not allow a second strike on a dead primer.

The major metal components of all Glock hand-guns are treated with Glock’s special hardening surface process called tenifer, which leaves the components nearly as hard as diamond, seals out moisture, and helps prevent corrosion. The surface hardening process penetrates the surface of the slide, barrel, and other metal components.The matte black finish is a final process applied to the surface, making the pistol extremely resistant to abrasions and scratches.

Should this black finish wear off after heavy and extensive use, the surface still retains its corrosion protection and durability.

The barrels of Glock pistols are made by a process called hammer forging and utilize both “hexagonal” and “octagonal” rifling, depend-ing on the model and caliber. Hammer forging involves bashing the barrel from all sides with hammers and forcing it into contact with a mandrel inside the barrel, which has the mirror image of the desired rifling on it.

The advantages of this type of rifling over traditional “land and grove” rifling are in-creased accuracy, higher velocities, and ease of cleaning. The higher velocities are due to a better bullet fit in the bore, which decreases gas leakage around the projectile. This also lends itself to easier maintenance and cleaning since less debris is left in the bore. The increased accuracy results from less physical upset of the bullet. Traditional rifling cuts deep grooves in the bullet when fired, which can upset the trajectory of the bullet. Due to the lack of these deep rifling marks, fired projectiles from Glocks were initially harder to identify. Forensic technol-ogy eventually adapted and was able to identify these “new” markings. Due to this rifling type, Glock does not recommend the use of lead-style bullets.

FUNCTIONThe Glock pistol is mechanically locked, short recoil operated, semi-automatic, and based on a Browning design. The Glock’s cycle of operation is as follows:

1. Feeding – removing a round from the magazine2. Chambering – placing a round in the chamber of the barrel and seating it3. Locking – closing and locking of the breech prior to firing4. Firing – ignition of the propellant in the cartridge5. Unlocking – removal of any block mechanism so that it may open6. Extracting – removal of the spent cartridge case from the chamber7. Ejecting – expulsion of the spent cartridge case from the gun8. Cocking – resetting of the trigger mechanism (with Glock, the striker is reset)

NOMENCLATURE

5

SCHEMATICS

6

7