Glocks are everywhere. To say they are the world’s most popular semi-automatic pistol may be putting it mildly. There are good reasons for that. Glocks are simple, rugged, and they just plain run. Maintenance is easy, especially since they all have the same basic design features. If you can run one Glock, you can run them all. And it doesn’t hurt that they are relatively inexpensive. Another plus is that magazines are easily found and often compatible with several models, depending on caliber and capacity.
The two most common Glocks are the Models 17 and 19. They are Glock’s oldest civilian models and are chambered in 9mm Luger, the world’s most popular pistol caliber. Their popularity, price, and the 9mm chambering mean new shooters often choose them as their first handgun. This leads to questions about magazine compatibility. We’ll address that momentarily, but let’s first look at how the guns are different, which aids in determining compatibility.
The Glock 17 Pistol
The Model 17 is the original Glock. You might wonder why inventor Gaston Glock designated the first Glock pistol as the “17.” Good question, and one I asked myself at one point. I assumed it took him 17 tries to get it right, but the answer is much simpler. The Model 17 was Glock’s first firearm patent, filed in 1981, but his 17th patent overall. So, he called it the “Glock 17.” The gun also has a 17-round capacity. I can’t say whether that factored into the designation.
On a side note, you “Die Hard 2” fans may be asking, “But what about the Glock 7?” Also a good question. Unfortunately, like many things conjured by the minds of Hollywood screenwriters, the porcelain Glock 7 isn’t real. Never was. But its description in the movie sparked a panic about supposedly “undetectable” firearms that built on gun controllers already referring to the polymer-framed Glock as a “hijacker special.” That morphed into the current hysteria surrounding so-called “Ghost Guns.” And really? A porcelain gun?
Anyway, the Austrian military adopted the Glock 17 as the Pistole 80 (P80) in 1983, and it became wildly popular among civilian shooters, who loved its simple reliability. But the 17 is a full duty-sized pistol, with a 4.49-inch barrel, an overall length of 8.03 inches, and it’s 5.47 inches tall. Those dimensions make concealment a challenge. Glock heard those concerns and went to work on a “compact” model.
The Glock 19 Pistol
By today’s standards, calling the Glock 19 a “compact” seems odd. In fact, many folks consider the 19 and other similarly sized handguns to be duty weapons. It is true that the Glock 19 and its peers (some would say clones) are popular among police and carried by many military units. But in 1988, compared to the Glock 17, “compact” was the right descriptor.
If Glock hit a home run with the Model 17, the 19 was a grand slam. Over 30 years later, the Glock 19 is still the semi-automatic handgun by which all others are judged. Yes, I know about the 1911, and I like it too. But, if you’re honest, the Glock 19 owns that title these days. I don’t particularly like Glocks (it’s a grip thing), and even I admit it.
The Glock 19’s dimensions aren’t all that much smaller than the 17’s, but a little goes a long way with carry guns. The Model 19 sports a 4.12-inch barrel with an overall length of 7.36 inches. The gun is 5.04 inches tall and weighs about an ounce and a half less than the 17 when both are empty. Again, that doesn’t sound like much, but the overall effect is significant. The new Glock flew off the shelves and does so to this day.
Do the Glock 17 and Glock 19 use the same magazines?
So, we get to the point of the article. Both pistols are double-stack 9mm guns. And with Glock’s simple design, compatibility is a fair question. The answer is, “It depends,” but determining compatibility isn’t difficult. It all comes down to magazine length, which is easily judged by magazine capacity, with one small exception.
When asking about Glock 17 and 19 magazine compatibility, you have to remember each gun’s standard capacity. That capacity does not count when using the 10-round mags required by several less-than-free states. We’ll get to those momentarily. But the Glock 17 normally holds 17 rounds of 9mm Luger. The Glock 19 normally holds 15 rounds.
The Glock 17 will accept any double-stack 9mm Glock mag with 17 or more rounds, whether that be 19, 21, 24, or 33 rounds. Or whatever else you run across in the aftermarket. I can’t keep up. The Glock 17 will not accept 15-round Glock 19 mags because they are not long enough.
The shorter Glock 19, however, will accept all Glock 17 compatible magazines, plus its own double-stack 15 rounders. It’s that simple. The mags won’t be flush and will stick out, but they will work just fine. Let’s move on to the 10-round magazines.
I’m sure you’re aware that some states restrict magazine capacity. Glock makes 10-round magazines for the unfortunates who live there. But the principle is still the same. 10-round magazines for the Glock 17 will work in both pistols. 10-round mags for the Glock 19 will not work in the Glock 17 because the grip, and therefore the magazine well, is longer.
A Few Other Compatible Models
Glock’s best feature, besides reliability, is the amount of cross-platform similarity and compatibility. That’s my opinion, anyway. Glock offers other double-stack 9mm pistols, namely the Models 26, 34, 45, and 19X. All those guns can use Glock 17 mags.
10 and 15-round Glock 19 mags, for the same reasons listed above, can be used by the subcompact Model 26, but not the others. Models 34, 45, and 19X all have the Glock 17 frame and, therefore, the longer grip that’s not compatible with the shorter Glock 19 mags. Here’s a hopefully helpful table breaking it down:
| Glock 17 | Glock 19 | Glock 26 | Glock 34 | Glock 45 | Glock 19X | |
| Glock 17 Mags | Yes | Yes | Yes | Yes | Yes | Yes (except Gen 5) |
| 10 & 15 Round Glock 19 Mags | No | Yes | Yes | No | No | No |
Generational Differences?
There are five generations of Glock pistols, helpfully referred to as Gen 1, Gen 2, Gen 3, Gen 4, and Gen 5. With one small exception, Glock magazines are compatible across all generations of mags and pistols. For example, a Gen 2 mag will work in a Gen 4 pistol and vice versa.
The one exception, which I have on good authority from actual Glock people with whom I associate, is that Gen 5 mags will not work in the Glock 19X. That’s because the 19X’s grip has a “silly lip” that won’t allow the Gen 5 magazine’s baseplate to seat properly.
A Word About Aftermarket Magazines
Glock has the best aftermarket support in the firearms world. The platform’s popularity demands it. That includes aftermarket mags. There are different levels of quality, but the rules laid out above still hold. A Glock 17 mag will work in all the other Glock double stack 9mm pistols. 10 and 15-round mags designed for the Glock 19 will only work in the Glock 19 and Glock 26.
Several companies make high-capacity drum magazines for Glocks because why not? Since these are aftermarket products, I cannot be absolutely certain that they all work with both the Glock 17 and 19. But I can say that the 9mm drum mags I have seen, including those sold here at GunMag Warehouse, indicate whether they are compatible with double-stack or single-stack pistols. All those double stacks, in turn, work with all the Glock double-stack 9mm pistols listed above, including the 17 and 19. Read product descriptions and/or the packaging. That should tell you for certain.
Not Rocket Surgery
When you come down to it, understanding Glock magazine compatibility only requires you to know a few things. First, what caliber is your gun? Second, is it double-stack or single-stack? Third, is the magazine in question’s capacity equal to or greater than your gun’s standard capacity? If you know the answer to all three of those questions, you’ve nailed the compatibility question.
Match the caliber, know whether you have a double-stack or single-stack pistol, and answer “yes” to the final question. Then buy the mag, or mags, with confidence. Your MIT acceptance letter will be in the mail.
