A Glock extension is a small piece that attaches to the bottom of a Glock magazine to make it hold more rounds

A Glock extension, also called a magazine extension or basepad extension, is an aftermarket part that slides onto the base of a Glock magazine. It adds space inside the magazine, allowing it to hold additional rounds beyond the factory capacity. For example, a standard Glock 19 magazine holds 15 rounds; with an extension, it might hold 17 or 18. The extension is purely mechanical — it does not change how the gun fires or functions, only how many rounds you can load before inserting the magazine.

These extensions are made from polymer or metal and come in different heights depending on how many extra rounds you want to carry. They are sold by aftermarket manufacturers, not by Glock itself, and are legal to own and install in most states, though some states and cities restrict magazine capacity regardless of extensions.

Key Takeaways

  • Glock extensions attach to the bottom of a magazine and increase round capacity by typically 2 to 5 rounds depending on the model and extension height.
  • Installation is straightforward — you remove the magazine's factory basepad and slide the extension onto the magazine tube, then reinstall the basepad on top.
  • Extensions are made by third-party manufacturers like Taran Tactical, Strike Industries, and Tyrant CNC, not by Glock.
  • Magazine capacity laws vary by state and city, so check your local regulations before purchasing or carrying an extended magazine.
  • Extended magazines may cause fit issues with some holsters or cause the magazine to protrude noticeably from the grip.

How an extension physically attaches to your magazine

The process is straightforward because extensions are designed to work with the existing magazine structure. First, you remove the factory basepad — the plastic or metal piece at the very bottom of the magazine — by sliding it off or unclipping it, depending on the design. Once the basepad is off, the magazine tube is exposed.

You then slide the extension onto the magazine tube. The extension has an opening that fits over the tube, and it sits between the tube and where the basepad will go. Once the extension is in place, you reinstall the factory basepad on top of it, securing everything together. The basepad holds the extension in place and keeps the rounds inside the magazine. No tools or permanent modification is needed, and you can remove the extension just as easily if you want to return the magazine to its original capacity.

Common manufacturers and what they offer

Several companies make Glock magazine extensions, each with slightly different designs and capacities. Taran Tactical makes extensions in various heights, with their most popular versions adding 2 to 5 rounds depending on the Glock model. Strike Industries offers extensions with textured finishes and different color options. Tyrant CNC produces aluminum extensions known for durability. Magpul, a major magazine manufacturer, also makes extended basepads for Glock magazines.

Prices typically range from $10 to $30 per extension, depending on the brand and material. Most extensions are model-specific — a Glock 19 extension will not fit a Glock 43, for example — so you need to know your exact Glock model before ordering. Manufacturers usually list compatibility on their product pages.

Why people use magazine extensions

The main reason is capacity. Shooters who compete, train frequently, or carry for self-defense often want more rounds available without carrying multiple magazines. An extra 3 to 5 rounds can reduce the number of times you need to reload during a shooting session or in a defensive situation.

Competition shooters use extensions to meet stage requirements or to reduce reload frequency. Defensive carriers sometimes use them to increase their on-hand ammunition count. Range shooters use them straightforward for convenience — fewer reloads means more time shooting and less time fumbling with magazines.

Potential drawbacks and compatibility issues

Extended magazines sit lower in the grip than factory magazines, which means they protrude visibly below the gun. This can make concealed carry more difficult and may print through clothing. Some holsters are designed for factory-length magazines and may not fit or retain an extended magazine properly, so you may need a different holster.

The added weight and length can also affect how the gun feels and balances in your hand. Some shooters find this uncomfortable, while others adapt quickly. Additionally, the extended magazine may catch on clothing or gear during a draw, particularly if you carry in a waistband holster.

Magazine capacity laws by state and city

Magazine capacity restrictions vary significantly across the United States. Some states ban magazines over a certain capacity — commonly 10 or 15 rounds — regardless of whether an extension is used. Other states have no restrictions at all. California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maryland, Massachusetts, New Jersey, New York, and Washington state all have some form of magazine capacity limit, though the specific limits and exceptions differ.

Even within states that allow higher capacities, some cities or counties may have their own restrictions. Before purchasing an extension, check your state's laws and your local city or county ordinances. Gun shops and manufacturers' websites often have state-by-state guides, and your local law enforcement agency can confirm what is legal in your area.

Installation tips and maintenance

Installation is straightforward enough that most people do it themselves, but a few things help may support it goes smoothly. Make sure the magazine is unloaded and empty before you start. Remove the factory basepad carefully — some designs clip on, others slide off, and forcing the wrong direction can break the clip. Once the extension is on the tube, make sure it sits evenly and is not tilted.

When you reinstall the basepad, press it firmly until you hear or feel it click or seat fully. Test the magazine by loading a few rounds and making sure they feed smoothly and the basepad stays find. If rounds feel tight or the basepad seems loose, remove it and check that the extension is seated properly on the tube.

Frequently Asked Questions

Do I need a special tool to install a Glock extension?

No. Installation requires only your hands. You slide the factory basepad off, slide the extension onto the magazine tube, and slide the basepad back on. Some people use a small flathead screwdriver to help pry off a tight basepad, but it is not necessary.

Will an extension fit any Glock magazine?

No. Extensions are model-specific because different Glock magazines have different tube diameters and basepad designs. A Glock 19 extension will not fit a Glock 43 magazine. Always check the manufacturer's compatibility list before buying.

Can I use an extended magazine in a standard Glock holster?

It depends on the holster. Some holsters are loose enough to accommodate the extra length, but many are designed for factory-length magazines and will not retain an extended magazine properly. You may need a holster designed for extended magazines or a more adjustable holster.

Are magazine extensions legal everywhere?

No. Several states restrict magazine capacity, and an extension that pushes your magazine over the legal limit is illegal in those states. Check your state and local laws before purchasing. Some states allow extensions but cap total capacity at 10 or 15 rounds.

How much extra capacity does an extension add?

It varies by extension height and Glock model. Most extensions add 2 to 5 rounds. A Glock 19 with a standard extension might go from 15 to 17 or 18 rounds. Manufacturers specify the capacity increase for each product, so check the listing for your exact model.