SIG SAUER P365 21-Round Magazine Black

SIG SAUER P365 21-Round Magazine — Black

Add extended capacity to a compatible 9mm P365-family pistol with this factory SIG SAUER 21-round magazine. Manufacturer part number 8901594 is built around the P365 magazine interface and provides an OEM option for range practice, training, competition, or maintaining a dependable spare. The extended design offers substantially more capacity than flush-fit P365 magazines while retaining the construction and fit specified by SIG SAUER.

Factory Materials and Construction

The magazine uses a steel body with a black-oxide finish for strength and corrosion resistance. A black polymer baseplate completes the extended lower section, while rear witness holes provide a convenient visual reference for loaded rounds. Its all-black appearance pairs naturally with standard black P365 configurations and keeps the magazine easy to identify alongside coyote-base alternatives.

• Manufacturer part number: 8901594
• UPC: 798681693443
• Caliber: 9mm Luger
• Capacity: 21 rounds
• Magazine body: Steel
• Finish: Black oxide
• Baseplate: Black polymer
• Loading reference: Rear witness holes

P365-Family Compatibility

SIG SAUER lists this magazine for numerous 9mm P365-family models, including the P365, P365X, P365-XL, P365-DH3, P365-XL COMP, P365-XMACRO, P365-XMACRO COMP, P365-AXG, P365-FLUX, and P365-FUSE. That factory-listed range makes it useful for owners who train with multiple P365 configurations. Always confirm the exact firearm model and follow the pistol manufacturer’s operating instructions before use.

Practical Extended Capacity

A 21-round magazine reduces reload interruptions during longer drills and practice sessions. It can be especially useful for structured training, competition stages, or keeping a higher-capacity factory magazine available as a backup. Because it is a genuine SIG SAUER component, it is designed for the P365 platform’s magazine well, catch, and feed geometry rather than serving as a generic aftermarket substitute.

The extended body projects below the grip more than a flush-fit magazine. Account for that additional length when choosing magazine pouches, storage cases, or concealment equipment. This listing is for one magazine only; the firearm and ammunition are not included.

Capacity and Legal Considerations

Magazine-capacity restrictions and shipping rules vary by state and locality and may change over time. Buyers are responsible for verifying that a 21-round magazine may be purchased, shipped, possessed, and used in their jurisdiction before ordering.