The Sig Sauer P320/M17 9mm 21-Round Extended Coyote Magazine is a factory handgun magazine built for the full-size P320, M17, and M18 pistols (Sig Sauer part no. MAG-MOD-F-9-21-COY). It uses a heat-treated steel tube for durability, wrapped in a black coating and capped with a coyote tan polymer baseplate that extends about an inch below the magwell to add 21-round capacity. A high-visibility orange follower makes it easy to spot remaining ammunition at a glance. Built to the same reliability standard as magazines issued with the U.S. Army’s M17, it’s a straightforward way to add capacity to a full-size P320 with a factory magwell installed. Competitive shooters and duty-minded owners both reach for this magazine when flush-fit capacity isn’t enough.

Key Specifications

• Chambered for 9mm.
• Holds a 21-round extended capacity.
• Fits the full-size P320, M17, and M18 pistols with a magwell installed.
• Tube constructed from heat-treated steel.
• Tube finished in black coating.
• Baseplate finished in coyote tan polymer.
• Features a high-visibility orange follower.
• Overall length of 8.4 inches.
• Built to the same standard as magazines issued with the U.S. Army M17.

Frequently Asked Questions

Will this magazine fit a standard flush-fit P320?

It requires a factory magwell to seat properly, so it’s intended for full-size P320, M17, and M18 pistols set up with one.

Why is the baseplate coyote tan instead of black?

The coyote tan finish matches the color scheme used on M17-pattern P320 pistols and accessories.

How much does this magazine add to grip length?

The extended baseplate adds roughly an inch below the magwell to reach 21-round capacity.

Buy the Sig Sauer P320/M17 9mm 21-Round Extended Coyote Magazine

Add extended capacity to your full-size P320 or M17 — Schaefer Defense ships fast from our Lubbock, TX gun shop, nationwide.