SIG Sauer P320 Full Size 9mm Magazine, 21-Round


A 21-round extended magazine for the SIG Sauer® P320-M17. The magazine may differ slightly from the image pictured. These original OEM magazines come with the P320 M17 and M18 variations. Made in Italy.

State and regional magazine capacity restrictions apply. Therefore, we cannot ship this item to California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maryland, Massachusetts, New Jersey, New York, Rhode Island, Vermont, Washington, Washington, D.C. and Cook County in Illinois.
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Shoot longer between reloads with this reliable factory 9mm P320 21-round extended magazine.

P320 21-Round Magazine Features

  • 21-round capacity
  • High-lubricity finish for reliable function
  • Removable base plate for easy maintenance
  • High-tensile spring for unmatched reliability and service life
  • Durable polymer follower
  • Complete steel body construction

Images may differ slightly from the actual product. These SIG Sauer high-quality magazines are sourced from multiple manufacturers and made to SIG’s exact specifications. Because of this, there may be slight differences in stamping and finish color.

21-Round Magazine Fit Guide

  • All P320 models, including the M-17 and M-18
  • It also fits the SIG P250

The 21-round extended magazine will fit all P320 models, including those with XSeries grip modules with or without the magwell installed. However, the extended length of this magazine will result in it sticking out quite a bit with Compact or smaller grip modules.

Additional information

Weight N/A
Dimensions N/A

Black, Coyote

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Many parts sold by Grayguns - including but not limited to triggers, trigger kits, internal components and spring kits - are intended for installation by a qualified armorer or gunsmith who is familiar with the firearm.

Although kits fit with no issues in a great majority of pistols, Grayguns cannot guarantee perfect functionality in every instance.

Due to varying tolerances present in all mass-produced firearms, professional fitting by a qualified armorer who is familiar with the pistol's action may be required.

Grayguns offers installation services for all parts kits we offer. If you have any issues or questions about the installation process, STOP IMMEDIATELY and contact the Grayguns Customer Service Team.