If you're running a Glock 20 or 20SF Gen 4 in 10mm, you need factory magazines that keep up with the caliber's potent power and your demanding use. This Glock Factory Magazine for Glock 20/20SF Gen 4 in 10mm Auto holds 15 rounds of full-power ammunition in a proven, durable package. Glock's factory magazines are engineered to the same exacting standards as the pistols themselves—they're what the gun was designed around, and they're what serious shooters depend on for reliability that matters when it counts.

The magazine body is built from high-resistance polymer reinforced with full-length steel inserts, giving you a magazine that's light enough to carry comfortably but tough enough to handle drops and hard use without warping or cracking. The internal spring is hardened steel, and witness holes numbered for each round let you quickly verify your load count without removing the magazine. Drop-free operation means the mag releases cleanly when you press the catch—no binding, no fumbling.

One thing worth knowing: Glock factory magazines can feel stiff when brand new, especially when loading the top few rounds. This is normal and by design—the spring and follower are engineered for long-term reliability. Most shooters find the magazine breaks in quickly with a few cycles or a day or two of storage under load. If you're adding to your 10mm loadout or replacing worn magazines, starting with factory Glock magazines ensures you're using exactly what your pistol was engineered to run.

Key Features

• 15-round capacity for Glock 20/20SF Gen 4 in 10mm Auto
• High-resistance polymer body with reinforced steel inserts for durability and lightweight carry
• Hardened steel internal spring for reliable feeding cycle after cycle
• Numbered witness holes for quick round-count verification
• Drop-free design for reliable magazine release
• Factory original engineering matched to your pistol

Specifications

Frequently Asked Questions

Will this magazine work in my Glock 20 Gen 4?

Yes. This is a factory magazine specifically designed for the Glock 20 and 20SF in Gen 4. It will function reliably in these models.

Why does the magazine feel stiff when I try to load it for the first time?

New Glock factory magazines are manufactured with tight tolerances and stiff springs to ensure long-term durability and reliability. The magazine may be difficult to fully load, especially the final rounds, until the spring has compressed slightly through normal use. Allowing the magazine to sit loaded for a few days or cycling it empty and full several times will speed up the break-in process.

What's included in the package?

You receive one factory Glock magazine. The magazine comes ready to use and does not include a mag pouch or loader.

Can I use this magazine in other Glock calibers?

No. This magazine is chambered specifically for 10mm Auto and is designed for the Glock 20/20SF Gen 4 platform. Use only in compatible firearms as specified.