Glock 21: Plastic Perfection in .45 ACP

by Peter G. Kokalis

Gaston Glock's Model 17 9mm Parabellum pistol was first introduced to the Ametican public by Soldier of Fortune magazine almost six years ago (see "Plastic Perfection," SOF, October '84). Since that time more than 2,000 U.S. local and federal law enforcement agencies have adopted or authorized the Glock as duty weapons. In addition to Austria, the armed forces of both Norway and the Netherlands have adopted the Glock. Law enforcement agencies and military units in Belgium, Canada, Ecuador, Hong Kong, India, Jordan, the Philippines, Taiwan, Thailand, Venezuela and West Gennany issue the Glock as their standard sidearm. Tens of thousands have been sold to the American public, and hundreds of thousands have been sold worldwide.

Now, at long last, this highly acclaimed handgun has been chambered for America's justifiably famous .45 ACP cartridge - mating 21st-century technology with an octogenarian of combat-proven effectiveness.

Dubbed the Glock Model 21, it is very similar in size to Glock's previously announced Model 20 10mm pistol. In fact, the frames appear to be identical. SOF's test specimen of a prototype Model 21 has an overall length of 8.27 inches, a height, with sights and inserted magazine, of 4.85 inches and a width of 1.2 inches (at the grips). The barrel length is 4.6 inches. The weight is 29.5 ounces with an empty magazine (almost 10 ounces less than a Colt Double Eagle or M1911A1). Almost 85 percent of this mass is accounted for by the steel components.

While some of the smaller components are interchangeable with the 10mm Model 20, you cannot assemble a Model 20 slide group to a Model 21 frame, as the locking block has been altered to prevent this. As with the other models in the Glock series, there are only 35 parts including the magazine. Glock says there are 33, but I count the sights and trigger spring cups as two components each. Of small consequence, as in either case this is still fewer than half the number of bits and pieces found in competing designs.

The Glock's remarkable success in just six years is matched by its even more remarkable design - the salient features of which are afl retained by the Model 21. Glock's only concession to conventionality is the pistol's method of operation. Short recoil operated, the barrel is locked to the slide by a single lug that recesses into the ejection port, in the manner of the SIG-Sauer series. During the recoil stroke the barrel moves rearward approximately 3mm until the bullet leaves the barrel and pressures drop to a safe level. The barrel then drops downward, separating from the slide and terminating any further motion. The slide's continued rearward movement and counter-recoil cycle are those of the Browning system.

Hammerless and striker-fired, the Glock's trigger and firing pin mechanisms are innovative and mostly unique. There is no manually operated thumb safety or decocking lever. A so-called "Safe Action" trigger system, patterned after that encountered on the Sauer Behorden ("Authority") Model 1930 caliber 7.65mm pocket pistol, constitutes the first failsafe. A wide, serrated, outer trigger encompasses a small, spring-loaded inner trigger, both fabricated from polymer. The outer trigger cannot be actuated, such as by contact with a holster, unless the inner trigger is depressed first. Thus the trigger can be pulled only from the center, not the edges.

A spring-loaded firing pin safety in the slide blocks forward movement of the striker, and is raised and deactivated by a projection on the sheet metal trigger bar as the trigger is pulled to its final rearward position.

When the trigger is in the forward position, the firing pin's spring remains lightly compressed. As the trigger is pulled about 10mm through its fust stage (with a pull weight of approximately 2.2 pounds), its full compression is almost complete. Removal of the finger from the trigger at this time will return the firing pin spring to its partially compressed, "relaxed" and completely safe state. Continued pressure at this point will 1) draw the fning pin fully rearward and its spring into complete compression; then 2) draw the T-shaped end of the trigger bar to its final rearward position in the trigger housing's stepped safety notch; so that 3) it is free to drop downward away from both the "connector" (sear) and a projection at the end of the striker to release the firing pin and fire the round.

The firing pin is rectangular in cross-section with a chisel-shaped tip. Although primers are left with an instantly identifiable indentation, the striker's unorthodox configuration produces less drag on the primer (eliminating the possibility of firing pin breakage) and concentrates its momentum onto a smaller area to insure positive ignition. Fluted firing-pin spring cups, which permit the Glock pistol to be fired underwater, are available to legitimate government agencies only. A stamped sheet-metal ejector, with an odd-looking inward cant, is permanently attached to the polymer trigger housing.

Further explanation of the connector is required. This sheet-metal component also serves as a disconnector. When the slide moves forward in counter-recoil, a thumb above the rail on the right side pushes the connector away from the trigger bar to prevent another round from being fired until the trigger is released and the trigger bar moves forward. The angle between the connector's upper face and its bottom face determines the trigger pull weight of the second stage. An angle of 90 degrees will produce the standard pull weight of 5 pounds. A pull weight of 8 pounds is achieved by increasing the angle to 105 degrees (this connector is stamped with a "+"). A pull weight of 3.5 pounds, available only with the Long Slide Target Model 17, is obtained when the angle is reduced to 75 degrees (stamped with a "-"). At the request of the New York State Police, a small polymer and steel component has recently been designed that increases the trigger pull weight to approximately 12 pounds when it is inserted into the trigger housing. That's too heavy for me, but should prove ideal for law enforcement agencies in transition from double-action revolvers. If the pistol is to be stored for any length of time, the trigger should remain in the retracted position to remove all tension of the firing pin spring.

This triple safe trigger mechanism is housed in a high-impact polymer frame that initiated the pistol's unjustified controversy (all the more strange as Heckler & Koch's VP70z and P9S pistols, both introduced more than a decade ago, were fabricated with largely polycarbonate frames). Four steel guide rails (about 0.4 inches in length) for the slide have been integrated into the injection molded frame - in pairs at the rear of the frame, and above and in front of the trigger guard. To meet BATF regulations, a steel plate carrying the serial number has been embedded into the frame in front of the trigger guard. The trigger guard has been squared off, recurved and checkered, but those who fire from the correct Weaver position will not employ this useless feature.

The grip-to-frame angle of the Model 21 remains that of the Glock 17/19, which is somewhat steeper than competing designs. There is a non-slip, stippled surface on the sides of the grip and both the front and rear straps are grooved and checkered. As there are no separate grip panels, the grip portion of the pistol, while larger in circumference than that of the Glock 17/19, accommodates normal-sized hands despite its large magazine capacity.

The locking block, which engages a 45-degree camming surface on the barrel's lower lug, appears to be the Glock's only investment casting. It is retained in the frame by the same steel axis pin that holds the trigger and slide stop. The trigger housing is attached to the frame by means of a polymer pin. A spring-loaded, sheet-metal pressing serves as the slide stop, which is protected from accidental manipulation by a raised guard molded into the frame. The slide lock, operated by a single bent flat spring, engages a step on the front of the bartel's locking lug to prevent the slide and frame groups from parting company during the counter-recoil stroke. The magazine catch-release, another polymer component - located where it belongs, on the left side of the frame, directly to the rear of the trigger guard - is held in place by an uncoiled piece of spring steel. Both interior surfaces of the magazine-well's mouth have a beveled contour to assist in the insertion of magazines.

Rectangular in shape, the slide is milled from bar stock using CNC (Computer Numerical Control) machinery. Three hardening processes are employed on both the slide and barrel. The final tenifer finish, .04 to .05 millimeter in thickness, produces a patented 69 Rockwell Cone hardness just below a diamond) by means of a nitride bath at 500 degrees Centigrade. Scratches, which are in this instance no more than deposits from the other object, can usually be removed with a cloth and solvent. This matte, non-glare finish is 99 percent salt water corrosion-resistant and meets or exceeds stainless steel specifications. It's also 80 percent more corrosion-resistant than any hard-chrome finish.

Milled into both the top and right side of the slide, the Glock's large ejection port enhances functional reliability. A large claw extractor, fitted to the slide at the rear of the ejection port on the fight side, maintains its tension from a spfing-loaded plunger, which, together with the firing pin assembly, are held in place by a polymer backing plate. Cocking serrations on the Model 21's slide are cut deeply and provide an excellent purchase when the slide is retracted.

As both the Model 20 and 21 are now manufactured in the U.S. at Glock's new Georgia facility, they are no longer issued with fragile adjustable sights (still an option, however) to meet BATF import regulations. High profile, combat-type, fixed sights are now standard. Four rear-sight heights are available: 6.1mm (lower impact, 6.5mm (standard issue), and the higher impact 6.9mm and 7.3mm. A rear sight mounting and adjusting device can be obtained by certified Glock armorers. The polymer front sight carries a white dot and the rear sight has a white outline. However, best of all, in my opinion, are the self-luminous, tritium, low-light-level sights with which the Model 21 can be fitted directly from Glock, Inc. These tritium crystals will last more than 10 years. Sight radius of the Model 21 is 6.75 inches.

Glock's hammer-forged barrels are also innovative. Called "hexagonal," the rifling lies somewhere between conventional land and groove and H&K's "polygonal" bores. The rifling's hexagonal profile (in cross-section a series of six small arcs connected by flat surfaces) provides a better gas seal, more consistent velocities, superior accuracy and ease of maintenance. The direction of twist is right-hand. Although not yet specified at the time of our test and evaluation, I expect the rate of twist will be close to the standard 1:16 inches for this cartridge. A single-coil spring under the barrel rides on a polymer guide rod, which is hollow to serve as a cooling air pump.

The Model 21 magazine is of the single-position-feed, staggered-column type with a capacity of 13 rounds. With one up the snout, that gives you 14 rounds of .45 caliber medicine. Magazine bodies, followers and floor plates are fabricated from polymer. The magazine bodies have steel liners and indicator holes starting with round No. 4 up to the capacity of the magazine. When new, Glock magazines will drop freely from the magazine-well. After use, however, the magazine walls will set widi an outward bulge that requires their removal by hand. In my opinion, this is a matter of small consequence. If you haven't solved your problem with 14 rounds, a pistol was an inappropriate choice for the confrontation. Each Model 21 is issued widi two magazines, a polymer magazine loader and cleaning rod and a nylon bristle bore brush. The polymer storage box has been designed for armory stacking and retention with a steel rod or chain. Suggested retail price is $598.

While somewhat different from the norm, there is nothing complex about the Model 21's disassembly procedures and, unlike the Colt Double Eagle, no component will part company from the slide or frame unless you intend it to do so. First, remove the magazine and remove any round in the chwnber. Then, and only then, pull the trigger. Wrap the four fingers of the right hand over the slide from the right side with the thumb wrapped around the rear of the frame and retract the slide about an 1/8-inch (any more than that and the trigger will move forward to prevent separation of the slide and frame). Pull the slide lock downward with the thumb and index finger of the left hand. While the slide lock is down, push the slide forward and off the frame. Push the guide rod forward and remove the rod and recoil spring. Push the barrel forward, lift up and pull it back out of the slide. No further disassembly is recommended. Do not attempt to manipulate the trigger system after the slide has been removed or you may damage the inner trigger's spring. Reassemble in the reverse order. To disassemble the magazine, merely squeeze the side walls at the base and slide off the floor plate.

There can be no question about the Glock design's levels of reliability or durability. In its 9mm Parabellum version, it has successfully passed tests every bit as rigorous as the U.S. XM9 trials, involving hundreds of thousands of rounds. That it was excluded from the most recent XM9 trials is a commentary on the U.S. Army's conventional mind-set, not the Glock design.

SOF's test and evaluation of the Model 21 did no more than confirm impressions already formed from tens of thousands of rounds fired through our Glock 17 and 19 pistols. There were no stoppages of any kind during the course of the 500 rounds fired through our test specimen. The frame's inherent elasticity dampens felt recoil considerably. As the barrel's axis lies close to the hand, the recoil momentum is perceived as an almost straight rearward thrust with much less muzzle climb that of either the Colt Double Eagle or a standard Govemment Model. Target reacquisition times between shots are minimal as the front sight barely leaves the point of aim if a strong Weaver hold is employed. Quite muzzle heavy, the Model 21 points instinctively and comes on target with great speed. With its clean and constant trigger system, the hit probability is high. There is, of course, no hammer bite to distract the shooter. The frame's grip ergonomics are excellent.

What about the accuracy potential? Most engagements with a handgun will take place at 21 feet or less. Firing a pistol from 50 yards off a Ransom rest will provide information concerning its theoretical accuracy potential, but nothing about its practical accuracy in a stress scenario. We fired the Model 21 at camouflaged combat targets from 21 feet in the Weaver position. The ammunition used in SOF's test and evaluation included Black Hills 185-grain Jacketed Hollow Point (JHP) and 230-grain Full Metal Jackets (FMJ), 230-grain U.S. military ball and 230-grain hard-cast round-nose reloads with a powder charge weight of 6.3 grains of Hercules Unique. Best results were obtained with the Black Hills 185-grain JHP, which consistently dumped a magazine of double-taps into a ragged half-inch group. The ejection path was consistently two to three feet to the right and rear.

I predict that the recently completed ammunition evaluation and wound ballistics penetration analysis by the FBI's Firearms Training Unit will deservedly draw attention away from the 9mm Parabellum cartridge and focus it once more on the venerable .45. The best 9mm load, Winchester's 147-grain subsonic JHP, was 30 percent less successful than the FBI/Sierra 10mm 180-grain JHP. That's a significant difference in performance. Remington's .45 ACP 185-grain JHP was only 2.5 percent less successful than the FBI/Sierra 10mm load. That's an inconsequential difference. Some law enforcement agencies, in copy-cat fashion, will jump on board the 10mm bandwagon. In my opinion, far more - both departments and individuals - will re-examine the .45. Most of us already have access to .45 ACP reloading dies and the components are plentiful. Long-established and battle-proven, the .45 has an aura steeped in the folklore of American history. The FBI tests should result in a revival of interest in the .45, only moderate acceptance of the 10mm and a waning of popularity in the U.S. for the 9mm Parabellum.

Glock's Model 21 has arrived at the right place, at the right time. With its large capacity magazine, brilliant design and superb reliability, we can expect its surge to the forefront in the wave of new popularity anticipated at both law enforcement and civilian levels for an ancient cartridge that makes a big hole and penetrates deep enough. Let's hope a compact version of the Model 21 with a single-column, eight-round magazine in a truly reduced envelope is shortly forthcoming.

First published in the June 1990 edition of Soldier of Fortune Magazine

GLOCK 21 Specifications
Caliber .45 ACP
Action Safe Action (constant double action mode)
Overall length (slide) 7.59 in. (193 mm)
Height, including magazine 5.47 in. (139 mm)
Width 1.27 in. (32.5 mm)
Barrel length 4.60 in. (117 mm)
Sight radius 6.77 in. (172 mm)
Rifling Octagonal profile with right-hand
twist of one turn in 15.75 in. (400 mm)
Weight, without magazine 26.28 oz. (745 g)
Weight, empty magazine 3.1 oz. (88 g)
Weight, full magazine ~12 oz. (~340 g)
Magazine capacity 13 rounds
Standard trigger pull ~5.5 lbs. (~2.5 kg)
Trigger pull length 0.5 in. (12.5 mm)
Number of safeties 3

information courtesy of GLOCK