CMMG Magazine Extension — FN Five-seveN, 5.7 x 28 mm, 10rd

The CMMG magazine extension increases the capacity of compatible FN Five-seveN 20-round magazines by ten rounds while remaining reversible and non-permanent. Installation takes only seconds and does not alter the factory magazine body. The extension uses a chrome silicon spring that is salt-water resistant and is described as not taking a set. Note that this extension is not compatible with the newest FN Five-seveN magazine designs.

Key Specifications

• Compatible brand fit is FN.
• Caliber compatible: 5.7 x 28 mm.
• Adds capacity of 10 rounds.
• Finish: Black.
• Model: Extension.
• Model fit: Five-seveN.
• Product type: Magazine Extension.
• Designed for FN Five-seveN 20 Round Magazine.
• Spring material: Chrome silicon (salt-water resistant and will not take a set).

This extension provides a straightforward, reversible capacity increase that preserves the factory magazine's integrity and is well suited for range use and competitive scenarios where extra rounds are desirable. Its quick installation and corrosion-resistant spring deliver practical, durable performance for users who value reliable, no-nonsense equipment.