The cynics in the group will say that all Glock pistols are the same and that choosing one is a simple thing. They would be wrong on both counts. Choosing a Glock pistol is something that should be given considerable thought.

Number of Glock Models Available by Caliber and Frame Style:

Subcompact Compact Standard Competition Long-Slide
.380 1 N/A N/A N/A N/A
9mm 4 7 5 5 1
.357 SIG 2 2 2 N/A N/A
.40 S&W 2 2 2 3 1
.45 ACP 4 N/A 2 2 N/A
.45 GAP 1 1 1 N/A N/A
10mm 2 N/A 2 N/A 1

When selecting a Glock pistol, you have 55 different handguns from which to choose. The company offers five frame sizes, seven different calibers and still makes pistols from the last three design “generations,” typically called Gen3, Gen4 and Gen5. The Gen4 and Gen5 pistols offer the option of the MOS system, which allows for mounting a Miniature Optical Sight atop the slide. Are you confused yet? Let’s try to sort it out, starting with the first and perhaps easiest choice: Do you want a thick or thin pistol?

Thick or Thin? (Single-Stack vs. Double-Stack)

If you desire a thin Glock (a pistol with a single-stack magazine), you have three choices: the Glock 36, the Glock 42 and the Glock 43. Each of these is in the subcompact frame category, and each has a magazine that holds six rounds. The Glock 36 is chambered in .45 ACP and, at its widest point, is 1.18 inches wide. The Glock 42 is chambered in .380 ACP and is just 0.98 inches wide. The Glock 43 fires the 9mm round and is 1.06 inches wide. While the difference in width may seem minor between the three pistols, it can make a big difference in carry comfort. The real difference in what gun folks call “shootability” comes in with the distance from the front of the trigger to the back of the grip. This trigger distance on the Glock 36 is 2.95 inches. It is just 2.4 inches on the 42 and 2.56 inches on the 43. This distance can have a big impact on how accurate you can be with a pistol, especially under stress.

Ideally, when you grab the pistol in a firing grip, your index finger should fall on the trigger very close to the first joint. Some trainers will tell you to press the trigger with the pad at the tip of your index finger. Others will say to operate the trigger by keeping the center of the trigger at your distal joint — that first joint back from the tip of your finger. Regardless of how your instructor teaches you to shoot, if you have very large hands, your index finger might reach too far across the trigger, causing accuracy problems during stressful rapid-fire.

When choosing a Glock, select one with a trigger distance that works well for your hand size.

The Glock Double-Stack Magazine?

If you opt for a Glock pistol with the traditional double-stack magazine, know that the trigger distance will be really close to 2.8 inches (as it is on most of the double-stack models).

Perhaps it’s time for a bit of a history lesson. Back in the 1980s, the original Glock design, the Model 17, used a 17-round magazine, with the cartridges loaded basically side-by-side and stacked in a staggered configuration. Glock pistols still use this design. This “double stack” allows for more ammunition in a shorter but thicker magazine. As a result, the overall width of most Glock double-stack pistols is about 1.25 inches. There is some slight variation depending on the caliber of the pistol, but that variation is usually within a few hundredths of an inch. This measurement can make a big difference in how the pistol feels in your hand and where your index finger comes to rest on the trigger.

When selecting a pistol, it is often best to go to a gun store or, better yet, a range that will allow you to rent several pistols to see which one feels best when you are firing it. Take the time and make the investment to test the gun you will be carrying to protect yourself and your loved ones.

Making History

Despite a popular misconception, the Glock 17 was not so-named because its magazine holds 17 rounds. The pistol got that designation because it was the 17th patent procured by the company. In 1982, Gaston Glock, an engineer with no experience in the firearms industry, decided to submit a pistol to the recently announced competition to replace the aging handguns of the Austrian military. Glock assembled a team of experts and, within three months, had a working prototype. The pistol passed a series of exhaustive trials and was selected for use by the Austrian military and police in 1982 and named the P80. By 1992, the pistol was being used in more than 45 countries. Forbes Magazine reports that Glock currently has nearly 65 percent of the handgun market in the U.S.

Glock Frame Size and Barrel Length

Glock offers five frame sizes, three of which are most suitable for concealed carry. Standard, Compact and Subcompact frames each offer pros and cons when it comes to personal defense. Typically the smaller frame sizes also have a shorter barrel, but recently the Glock 19X married the full-sized frame of the Glock 17 to a compact slide and barrel of the Glock 19 to create what amounts to a hybrid pistol.

The frame is what makes a pistol concealable. Barrel length really doesn’t matter when it comes to concealment because, with the exception of in a vertical shoulder holster, the barrel is more often than not inserted in the holster running parallel to the leg or torso. As a result, a gun with a smaller, shorter frame is easier to conceal. At the same time, that frame is more difficult to grip. Most shooters with average-sized hands can’t get all three fingers on the grip frame. Remember, the index finger goes to the trigger, leaving the middle, ring and pinky fingers to grip the frame. On a Glock subcompact frame, the pinky really has no place to go and typically rests under the baseplate of the magazine. Some people find this uncomfortable, and some just don’t mind at all. Again, you will have to shoot the gun to see how you like it. You could buy an extended magazine baseplate, but that really defeats the purpose of choosing the subcompact frame. We’ll talk more on magazines later.

The compact frame typically allows shooters with large hands to get all three fingers on the frame while firing. Compact Glock pistols have a barrel and slide that is about ½ inch shorter than Standard models. On the topic of Standard models, these are typically known as duty guns, carried by police and military personnel. With the right holster, a Standard-model Glock can be concealed, but the gun brings added weight and size, making concealment less comfortable. The trade-off is a personal choice typically based on the amount of ammunition the shooter wishes to carry.

Back to Magazine Capacity

The beauty of the Glock line is that guns of the same caliber can use magazines of that caliber interchangeably. Let’s use 9mm as an example. A Glock 26 carries a magazine that fits flush to the frame and holds 10 rounds. If you choose, you may use a Glock 19 magazine that holds 15 rounds or a Glock 17 magazine that holds 17 rounds. These magazines will stick out the bottom of the Glock 26 grip frame, but they will function perfectly. This means you could carry the Glock 26 in your holster, easily concealed, with 10 rounds in the magazine, but have a spare magazine of either 15 or 17 rounds if you need it.


Glock pistols may look similar, but there are several subtle differences between the models and calibers that can make a big difference in concealed carry comfort and accuracy when firing under stress. Before you buy a Glock (or any gun, for that matter), you should try several and choose the pistol that fits your hand and your concealed carry needs the best. You are looking for a pistol that you are willing to carry every day and train with very often. You cannot overlook comfort and fit when it comes to making your choice. Glock even has a fun little quiz to help you compare models.

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