SIG SAUER P320/M17/M18 9mm 21-Round Coyote Magazine

SIG SAUER P320-M17/M18 9mm 21-Round Coyote Magazine

Add factory capacity to a compatible SIG SAUER pistol with the MAG-MOD-F-9-21-COY extended magazine. This genuine SIG magazine is chambered for 9mm Luger and holds 21 rounds, making it a practical choice for range sessions, training, competition, duty-support equipment, or owners who want an original-equipment spare.

SIG SAUER identifies this exact model as a P320-M17/M18 magazine. Its extended configuration provides four additional rounds compared with a standard 17-round full-size magazine, while the coyote-colored polymer baseplate complements the M17’s military-inspired color scheme. The magazine uses a steel body, double-stack internal layout, and side witness holes that help the user monitor loading status.

Factory Design

Magazine reliability depends on more than capacity. Feed-lip geometry, spring pressure, follower travel, magazine-catch placement, and baseplate retention all affect how cartridges are presented to the pistol. As an original SIG SAUER component, this magazine is manufactured around the intended dimensions and operating geometry of compatible P320-family pistols.

The extended baseplate creates a positive gripping surface for insertion and removal. It also makes the magazine easy to distinguish from standard-capacity magazines in a range bag or carrier. The 21-round body extends below the grip rather than fitting flush, so buyers should account for the added length when selecting magazine pouches or storage cases.

Compatibility

• Designed for 9mm SIG SAUER P320, M17, and M18 pistols
• Compatible with full-size and carry-size P320-family configurations that accept full-size magazines
• Not intended for compact grip modules that cannot accept full-size P320 magazines
• Not compatible with P226, P229, P365, or other unrelated SIG magazine patterns

Confirm the pistol model, grip-module size, caliber, and magazine restrictions before ordering. P320-family grip modules vary in length, and the extended magazine will protrude below shorter compatible grips.

Product Details

• Manufacturer: SIG SAUER
• Manufacturer part number: MAG-MOD-F-9-21-COY
• UPC: 798681599592
• Platform: P320 / M17 / M18
• Caliber: 9mm Luger
• Capacity: 21 rounds
• Magazine type: Double stack, extended
• Magazine material: Steel
• Baseplate material: Polymer
• Baseplate color: Coyote
• Witness holes: Side
• Quantity: One magazine

Care and Responsible Use

Inspect the magazine before use for dents, damaged feed lips, a loose baseplate, debris, corrosion, or unusual follower movement. Keep it clean and dry, and follow SIG SAUER’s guidance for magazine inspection and maintenance. Do not modify the body, spring, follower, feed lips, or baseplate. Test each magazine with the intended pistol and ammunition before relying on it for defensive or duty use. A 21-round magazine may be restricted in some jurisdictions; confirm that purchase, possession, transport, and use are lawful at the destination.