Agency Arms Magazine Extension for SIG P320 17-Round +5 – Black

The Agency Arms Magazine Extension increases capacity of factory SIG P320 17-round magazines by five rounds, bringing total capacity to 22 rounds. Designed for shooters who want extended capacity without switching to a larger grip module, this extension maintains a clean profile while adding meaningful round count for competition, duty, or home defense applications.

Machined from billet aluminum with a Type III hard-anodized black finish for corrosion resistance and durability. Installation requires disassembly of the factory magazine baseplate and replacement with the Agency extension and included spring. The extension adds minimal length to the magazine while preserving reliable feeding. Some fitting or adjustment of the spring may be required depending on magazine generation and condition.

• Part Type: Magazine Extension
• Compatible Firearms: SIG P320 (17-round factory magazines)
• Capacity Increase: +5 rounds (17rd to 22rd total)
• Material: Billet Aluminum
• Finish: Type III Hard Anodized, Black
• Installation: User-installable with basic tools; gunsmithing not required
• Includes: Magazine extension, spring