FAB Defense FX4310B 4-Round Mag Extension for Glock 43 - Black Matte Polymer

The FAB Defense FX4310B 4-round mag extension for Glock 43 turns your single-stack carry gun into a higher-capacity option without swapping platforms. If you've felt cramped by the Glock 43's standard 6-round magazine, this black matte polymer floor-plate replacement brings you up to 10 rounds total—a meaningful jump for self-defense or backup duty. The engineering here is straightforward: it works with your existing magazine spring, so you're not buying a whole new magazine assembly.

What sets this extension apart is the ergonomic design. Shooters get contoured finger indents molded into the base pad, giving you a secure purchase during mag changes and reloads. More importantly, once installed, the extension lets your hand achieve a full grip on the gun itself—something the stock 6-rounder often prevents on smaller-handed operators. You're not compromising trigger control or presentation for that extra capacity.

The body is fiberglass-reinforced polymer, durable enough for range work and everyday carry without adding unnecessary weight. The matte black finish blends with most Glock 43 setups and resists glare. This is a purpose-built upgrade for shooters who carry a 43 but want the flexibility of 10-round mags for range time, training, or as a spare loaded mag.

Key Features

• Adds 4 rounds to Glock 43 magazine (10 rounds total)
• Works with original magazine spring—no new mag required
• Contoured finger indents for secure magazine handling
• Enables full grip on the handgun when magazine is inserted
• Fiberglass-reinforced polymer construction
• Matte black finish

Specifications

Frequently Asked Questions

Will this mag extension work with my factory Glock 43 magazine?

Yes. The FX4310B is designed as a floor-plate replacement and uses your original magazine spring, so you're upgrading your existing mag without purchasing a new one.

Does the extension actually let me grip the gun fully?

That's the goal. The extension's ergonomic design and contoured finger indents are meant to allow a full grip on the handgun when the magazine is seated. Results vary by hand size, but it's specifically engineered to address the grip limitations of the Glock 43's standard 6-round magazine.

What's included?

You receive the FAB Defense FX4310B floor-plate extension itself. You'll need your existing Glock 43 magazine to install it.