FN® 509 | 21rds | CO₂ | Magazine | Cybergun

FN® 509 | 21rds | CO₂ | Magazine | Cybergun

This is a low-cap CO₂ magazine by Cybergun, designed as a spare or replacement airsoft magazine for the FN Herstal 509 gas blowback replica. The magazine is constructed from metal and uses a CO₂ cartridge as its power source. With a capacity of 21 BBs, this magazine is part of the officially licensed FN Herstal x Cybergun accessory line, tailored to the replica built by KWC. This makes this pistol magazine a direct match for both training and skirmish use.

Technical specifications and compatibility

The magazine features a metal housing with a black finish and a product weight of 295 g. It is powered by a CO₂ cartridge, with a steel spring ensuring consistent and reliable BB feeding during firing. Gas pressure may vary with temperature: in mild conditions or indoor skirmishes, CO₂ performs reliably, while performance may decrease slightly in cold weather. This GBB (gas blowback) magazine is specifically compatible with the FN platform, namely the FN Herstal 509 (KWC) airsoft replica. As a low-cap variant, the BBs are held securely in place and do not rattle during movement or running — unlike hi-cap magazines.

Practical use

Insert a CO₂ cartridge into the base of the magazine and tighten it until the gas is connected. Then load up to 21 BBs of 6mm through the feed opening. The steel spring pushes the BBs upward in a controlled manner, ensuring reliable feeding with every shot. The magazine is a direct drop-in fit for the FN509 replica, allowing for quick changes during a game. Please note that CO₂ operates at higher pressure than Green Gas, which provides consistency but also places greater stress on internal components.

Who is this magazine suitable for?

This gas-powered airsoft magazine is intended for owners of the FN Herstal 509 (KWC) replica who are looking for a spare or replacement magazine. The low-cap capacity of 21 BBs particularly appeals to tactically minded players and milsim participants who value realistic reload moments and quiet movement. The metal construction contributes to durability and reliable performance in the field.

Ready to add the FN® 509 | 21rds | CO₂ | Magazine | Cybergun to your loadout?