Shark Coast Tactical Magazine Extension +5 for Glock 17

The Shark Coast Tactical plus five magazine extension for Glock 17 magazines is a simple, dependable way to carry more rounds without buying more mags. It replaces your factory base plate, adds five rounds to overall capacity, and ships with a replacement spring so feeding stays reliable at the new full count. Machined from 6061 aluminum, it is built for the drops and hard knocks magazines collect during serious practice.

What the Shark Coast Tactical extension changes on a Glock 17

The Glock 17 magazine is one of the most proven feeding devices ever made, and this part extends it rather than reinventing it. You keep the magazine body you already trust and simply gain length at the bottom.

For competitors, that means fewer reloads on long stages and fewer chances to fumble a magazine change under a timer. For home defense, it means more rounds in the gun before you ever touch a spare.

For everyone else, it is the cheapest way to turn a shelf of standard magazines into a shelf of high capacity magazines.

A Shark Coast Tactical extension also adds usable grip length on the magazine itself, which shooters with larger hands notice immediately during reloads. There is more to grab and more to strip out if a magazine ever hangs up.

Features worth paying attention to

The parts count is low, which is exactly what you want in something that has to work every time.

• 6061 aluminum body machined to replace the factory base plate.
• Five additional rounds of capacity per magazine.
• A durable replacement spring included in the package.
• Installation that mirrors routine magazine disassembly, no gunsmithing needed.
• Pricing that makes upgrading several magazines realistic.
• Built to survive the drops that end polymer base plates.

Specifications and why the spring matters

Adding length to a magazine without addressing the spring is where cheap extensions fail. A stock spring stretched over a longer column loses the tension it needs on the last few rounds, and that is precisely when a failure to feed shows up.

Including a durable replacement spring solves that at the root, so the magazine feeds the same at round twenty two as it did at round one. The 6061 aluminum body handles the mechanical side, protecting the base of the magazine from the impacts that come with speed reloads onto hard surfaces.

6061 is the sensible alloy choice here rather than a marketing one. It machines cleanly, resists corrosion, and holds threads and retention features without the brittleness that shows up in harder, less forgiving materials.

The result is a Shark Coast Tactical part that behaves like a factory component instead of an add on. Nothing about the manual of arms changes once it is installed.

Installation, care, and the fine print

Installation follows the same basic steps as routine magazine disassembly, so you can have it fitted in minutes at the kitchen table. Fully unload the magazine, control the spring tension as the base plate comes off, fit the new spring and extension, and verify everything is locked before you load it again.

After fitting, load to full capacity and run the magazine in the pistol to confirm function. Keep the aluminum clean and check the retention periodically, especially if you drop magazines regularly during practice. You can find spare Glock magazines and other upgrades in our magazines and parts upgrades section.

Confirm your magazine pouches still retain the extended magazine properly before a match or a duty rotation. The added length usually clears fine, but it is worth checking once rather than discovering it on the clock.

Note that this is an aftermarket accessory. It is not manufactured, authorized, endorsed, or warranted by Glock, and Glock makes no compatibility representations.

More rounds, a better spring, and an aluminum base that outlives the polymer it replaces. For a Glock 17 owner who already has magazines on hand, this is one of the highest value upgrades on the shelf. Ships direct to your door, no FFL required.