The Glock is the most popular police service pistol brand in the United States. In the commercial sector, many gun dealers acknowledge that Glock is not only their best-selling handgun, but their best-selling firearm. There are several reasons for this. This includes excellent aftermarket customer service, but the reasons for this popularity mainly boil down to a couple of key factors. One is the user-friendliness of the Glock platform. Another is the broad array of sizes and calibers available. The problem with all these choices is that it can be difficult to find the right Glock for your needs. Here we address all the differences and choosing a Glock that’s right for you.
Understand Your Needs
With a consistent, easy trigger pull and no sharp edges that bite the hand, Glock pistols are easy to shoot. There is no simpler pistol to learn to shoot well. Insert magazine, cycle slide to chamber a round, squeeze the trigger to fire, and repeat as necessary. Elements of the handgun manual of arms such as on-safe/off-safe, double-action/single-action, and decocking are all absent from the Glock handling protocol. Every trigger pull, from first to last, is exactly the same. If training time is limited, a simple design such as the Glock comes into its own. Prospective buyers need to be aware that choosing a Glock revolves around size, caliber, and personal needs.
The very first Glock, the Glock 17, established itself as a “service pistol” par excellence. That length, in turn, became the “standard size” Glock: a 4.5-inch barrel with slide of commensurate length, and a full-length grip-frame housing a full-length magazine.
That Glock 17, now in its fourth generation of design advancement, is chambered for the 9×19 cartridge, also known as 9mm NATO,9mm Luger, and 9mm Parabellum. Safe to carry fully loaded with a round in the chamber, it holds 17 more in its standard magazine.
In 1990, the same Glock format was introduced chambered for the then-new .40 S&W cartridge. Known as the Glock 22, this pistol is believed to be in use by more American police departments than any other. Its standard magazine capacity is 15 rounds.
Next, Glock chambered the same gun for the .357 SIG cartridge, and called it the Glock 31. That bottlenecked round shares overall length and case head dimensions with the .40, so by simply interchanging the barrels the shooter can change his Glock .357 to .40, or vice versa. Glock 31 magazines will work with .40, and Glock 22 magazines will work with .357 SIG cartridges.
With one caveat, the Glock 37 pistol in caliber .45 GAP is the same size as the pistols listed above. That one difference is slide thickness: on the Glock 37, the slide is wider, sufficiently so that it comes standard with the oversize slide-stop lever that is merely optional on the other standard size service models. A Glock 37 magazine is designed to hold ten rounds of .45 GAP.
Determined to be “double-action-only” by the Bureau of Alcohol, Tobacco, Firearms and Explosives, Glock’s Safe Action trigger is available in multiple formats. The standard is the 5.5-pound with standard trigger return spring, designed to give an overall pull of that weight. The shooter will experience a two-stage pull, rather like an old Springfield or Mauser bolt-action rifle trigger. The first stage is a relatively long, light take-up, followed by a shorter completing movement with more resistance. Glock shooters find it easy to “ride the link,” allowing the trigger to return forward from the last shot only until the sear engagement is felt, and then repeating the press.
Some police departments, such as Miami PD and the San Bernardino County Sheriff’s Department, have over the years seen fit to install heavier connectors in their issue Glocks. This would be the 8-pound. Butch Barton, who won more Gunny Challenge Glock matches than anyone else, long favored this set-up in his Glocks because he felt it gave him a crisper release. The 8-pound connector has not become widely popular elsewhere, however.
On the other end of the scale is the 3.5/4.5-pound connector, which debuted with the Glock 17L match pistol. Now known by the 4.5 pound designation, it registers that weight when the trigger is pulled from the center, where most of us place the index finger, and can go down to 3.5 pounds due to leverage when weighed at the bottom, or toe, of the trigger. Very popular among competitive shooters, it is sternly warned against by Glock for “duty pistols” or self-defense guns, unless used in conjunction with a New York style trigger return spring unit.
The NY-1 Trigger
Twenty-some years ago, at the behest of the New York Police Department, Glock created the New York Trigger, now known as NY-1. This device replaces the standard trigger return spring and gives a firm resistance to the still-two-stage trigger from the very beginning of the pull. When mated with the 5.5-pound connector, the NY-1 brings pull weight up into the 7- to 8-pound range. A Mid-western state police agency pioneered the practice of mating the 3.5-pound connector with the NY-1, which gave a very smooth and uniform pull in the 6-pound weight range. This combination has been Glock approved for duty/defense guns across the board for several years now. For NYPD, Glock also developed a “New York Plus” module, now known as the NY-2, which with the standard 5.5-pound connector brings pull weight up into the 11- to 12-pound range. To my knowledge, it is used only by NYPD and the New York State Parole Board.
This writer recommends following Glock’s guidelines and only going with the 3.5/4.5-pound total pull in a competition gun. Some wonder why that system is standard in the Tactical/Practical guns; they need to look at the Glock website (glock.com) and observe that those pistols are listed under the Sport Shooting and Enthusiast categories, and not under Police, Military, or Personal Defense. It is Glock’s policy to ship Glock 34s and Glock 35s ordered by police departments with the standard 5.5-pound trigger system, and it is worth noting that when the Kentucky State Police adopted the Glock 35, they ordered them with NY-1 triggers.
Fitting the Shooter’s Hands
Gaston Glock took great pains to shape his original pistol to fit the hand of an average-sized adult male. Going on the assumption that the barrel should be straight in line with the long bones of the forearm and the pad of the distal joint of the trigger finger should be centered on the trigger, he absolutely achieved that hand-fit parameter. As Glock pistols became more popular, the company worked on different approaches to fit a wider range of hand sizes and finger lengths.
The earliest approach was the introduction of the Glock 36. By taking the compact Glock 30 of the late 1990s and replacing its double-stack magazine with a narrower one that held just six .45 Auto rounds, Glock created its first slim-gripped pistol. The width of the slide was also reduced, making it an all-around “slim-line” gun. The reach from the back strap of the grip to the trigger was the shortest of any Glock. This was a boon to not only short-fingered shooters but also those “old school” gunnies who preferred to contact the trigger with the distal joint of their index finger instead of the pad. In doing so, Mr. Glock made the process of choosing a Glock far easier than other firearm manufacturers.
Next, in the large-frame guns, came the SF (Short Frame) series. Shorter in front-to-back grip measurement than the originals, the Glock 21 SF, Glock 30 SF, Glock 20 SF, and Glock 29 SF allowed the user of these powerful guns to grasp proportionally more of the grip frame, and get their index fingers deeper into the trigger guard.
Gen4 & Gen5
In 2010, GLOCK introduced its Gen4 series. The first-generation Glocks had a relatively smooth gripping surface. To improve hand traction, in the 1980s, the company went to a second-generation approach, with checkering. Both generations had flat front straps on their grip frames. The third generation added finger grooves on the front strap.
Gen4 differs from its predecessors in two important respects. The most obvious is that the dimension between the center of the trigger and the point on the backstrap where the web of the hand rests has been reduced. The pistol is provided with two easily attached backstrap inserts. One of the inserts brings the feel to roughly that of a previous-generation Glock of the same model. The other extends further, adapting the gun to very large hands and resembling a Glock 21 or Glock 20 in feel and trigger reach.
Gen5 was later introduced in 2017. Gen5 models offered improved ergonomics and reliability. What sets Gen5 apart from its previous iterations is that many of its parts cannot be interchanged with older models. While it’s not a critical factor in choosing a Glock, you may want the versatility of being able to swap out certain parts at your convenience.
The 9×19 was the very first Glock chambering. It remains the most popular internationally and among private handgun purchasers in the United States. Its mild recoil makes it an ideal choice for a new Glock shooter. 9×19 is the lowest-priced centerfire handgun ammunition available in the U.S., making it very cost-effective for skill-building practice.
Which model? The Glock 34 is the single most popular handgun at the IDPA National Championships. In 2010, it was the winning gun in the Stock Service Pistol Division and it also captured the Women’s Championship in the capable hands of Randi Rogers. However, its 5.3-inch barrel is a bit long for all-around concealed carry.
The Glock 19 is an excellent all-around choice. In New York City, it is by far the most popular police pistol—large enough to serve as a uniform holster weapon, compact enough for easy, discreet carry by plainclothes officers and off-duty personnel. It is also surprisingly competitive in action shooting matches. David Harrington has won many IDPA matches with his Glock 19. Ace GSSF shooter, Mike Ross, uses a Glock 19 in that type of competition by choice, finding that its shorter slide seems to track straighter upon recoil between shots. Designed for 15+1 cartridge capacity, the Glock 19 is only two rounds short of the longer-framed Glock 17, Glock 34, and Glock 17L pistols firing the same 9×19 round.
The little Glock 26 is hugely popular as a concealed carry pistol and police backup gun. Remarkably accurate despite its small size, it tends to be the most popular pistol at BUG (Back-Up Gun) matches. At GSSF shoots, the Glock 26 dominates the subcompact category. It is not uncommon to see shooters score higher with their Glock 26 than with their Glock 17.
In American policing, .40 caliber is the most popular. More than 20 years ago, police realized that the debate over the typical 16-shot 9×19 versus the then-standard eight- or nine-shot .45 Auto could be very easily rendered moot by a 15+1 shot Glock 22 chambered in .40.
The Glock 23 compact is a hugely popular concealed carry pistol. In some police departments (Boston, Massachusetts, for example) issue it as standard for both uniform and detective divisions. It’s also the standard issue pistol for the FBI, though the Bureau gives agents the option of the larger Glock 22. With 15+1 .40-caliber rounds on board, the Glock 23 represents an excellent balance of size and power.
The subcompact Glock 27 holds nine .40 rounds in its standard magazine and a tenth in the firing chamber. Because—like all small Glocks—it can use the longer magazines of its larger siblings in the same caliber, it is one of the nation’s most popular off-duty backup guns, and is in extremely wide use among the concealed carry population.
At the other end of the Glock .40 size spectrum, the Glock 35 is extremely popular in USPSA (United States Practical Shooting Association) competition. Its cartridge “makes major” in terms of power factor, essentially giving the shooter bonus points for hits outside the center scoring ring.
The bottlenecked .357 pistol cartridge is not the most popular, but it certainly has an enthusiastic and growing following. Spitting a 125-grain bullet at 1,350 FPS (feet per second), this round hits with authority and has a very flat trajectory over a long range. The standard-size Glock 31 is the most popular model among police. Meanwhile, the compact Glock 32 seems to be more popular among armed citizens lawfully carrying concealed. The subcompact Glock 33 is a little 9+1 shot powerhouse that carries the payload of two 5-shot .357 Magnum revolvers at once but with distinctly less recoil and muzzle blast. The Glock 33 is a popular backup gun for officers who carry the larger .357, and it also makes an excellent concealed carry pistol.
In 10mm Auto, the Glock 20 has been perhaps the most durable pistol of its caliber since 1990, and probably the most popular. Holding 15+1 rounds of hot loads, the late Chuck Karwan—a highly respected small arms authority, and veteran of heavy combat in Vietnam—considered the Glock 20 to have more power per standard load than any other readily “carryable” handgun. Its compact version is the Glock 29, a virtual twin to the .45 Auto Glock 30.
The 10mm Auto Glocks have an enthusiastic following in dangerous game country among outdoor folk who want to have more than six shots if charged by a large, ferocious bear. With heavy, full metal jacket bullets, the 10mm Auto gives more penetration than other standard-caliber autopistols.
An American favorite for more than a century, the .45 AUTO cartridge is found in no fewer than three Glock formats. These are the service-size Glock 21 (13+1 rounds), the subcompact Glock 30 (10+1 rounds), and the subcompact, Slimline® Glock 36 (6+1 rounds). Due to their design, the Glocks in .45 Auto are famous for their relatively soft recoil.
Finally, there is Glock’s own cartridge, the .45 G.A.P. (Glock Auto Pistol). Duplicating the ballistics of the traditional standard pressure .45 AUTO (and occasionally slightly exceeding them), G.A.P. ammunition can be had in bullet weights of 185, 200, and 230 grains.
Designed to be shorter overall than a .45 AUTO or 10mm AUTO cartridge, the .45 G.A.P. can fit into the smaller frame of the standard Glock line. This gives the shooter a .45 that better fits smaller hands. According to testing by Florida Highway Patrol, it allows shooters with larger hands to control recoil better with a .45 G.A.P. than with a larger-framed pistol firing equivalent .45 Auto loads. The .45 G.A.P. Glocks are the Glock 37 in full-size format (10+1 rounds capacity when fully loaded); the compact Glock 38 (8+1 rounds); and the subcompact “Baby” Glock, the Glock 39 .45 G.A.P., which holds a total of 6+1 cartridges.
Different Glock Models & Their Calibers
Glocks come in different sizes to fit different needs. If maximum concealability is a key parameter, there is the subcompact “Baby” Glock with a 3.43-inch barrel. It is roughly the size of a snub-nose .38 revolver but more square. It holds far more ammunition and is much easier to shoot. Part of learning choosing a Glock is knowing ahead of time the different firearm calibers – along with their firepower and their cost.
- G26 Gen4
- G26 Gen5
- G43X MOS
- G26 Cut
- G27 Gen4
- G27 Gen5
- G29 Gen4
- G29 SF
- G30 Gen4
- G30 SF
- G19 Gen4
- G19 Gen4 MOS
- G19 Gen5
- G19 Gen5 MOS
- G45 MOS
- G48 Black
- G48 MOS
- G19 Gen4 Cut
- G23 Gen5
- G23 Gen5 MOS
- G23 Gen4
- G23 Cut
- G32 Gen4
- G34 Gen4
- G34 Gen4 MOS
- G34 Gen5 MOS
- G41 Gen4
- G41 Gen4 MOS
- 10mm Auto
- G40 Gen4 MOS
- G17 Gen4
- G17 Gen4 MOS
- G17 Gen5
- G17 Gen5 MOS
- G47 MOS
- G17 Gen4 Cut
- G22 Gen5
- G22 Gen5 MOS
- G22 Cut
- G20 Gen4
- G20 SF
- G20 Gen5 MOS
- G21 Gen4
- G21 SF
- G21 Gen5 MOS
Many Glocks are available in “C” models. This compensates for recoil with ports that go through both the barrel and slide near the muzzle. These direct burning, expanding gases upward when the shot is fired, forcing the front end of the pistol down to compensate for muzzle rise. Recoil is an important factor in choosing a Glock. Be sure to demo as many pistols as possible.
Glocks are simple, versatile, and built by a company determined to make a pistol to fit virtually every adult hand. It’s easy to see why Glock pistols are so popular in both the civilian market and the police sector. Hopefully, you are now more well-informed on choosing a Glock and are ready to make a worthwhile investment.