+1 Extension for Sig Sauer P320 21rd Magazine


Designed for:

  • Model: All Sig Sauer P320 models except Subcompact
  • Grip Module: Full-Size / Full-Size XGRIP / Carry / XCarry / Compact / XCompact
  • Magazine:  Only the extended 21 round 9mm or 18 round .40 S&W magazine
  • NOTE: The 17 round or smaller magazines will not work


  • Adds 1 round to 21 round 9mm magazine for a total of 22 rounds.
  • Adds 1 round to 18 round .40 S&W magazine for a total of 19 rounds.
  • Fits in a 140mm gauge for competition shooting
  • Fits all Sig Sauer P320 Pistols when using the 140mm magazine.
  • Includes unique retainer plate
  • Suitable for 9mm or .40 S&W
  • Tolerant of repeated dropping
  • Added weight aids in magazine release
  • Made from 6061 Aluminum
  • Black Hard Coat Anodizing
  • Made in USA
SKU: N/A Category:


An improvement over the polymer OEM base pad, our P320 extensions are machined out of 6061 aluminum. They are much more tolerant of being dropped on rocky or cement surfaces for heavy tactical or competition use. The added weight of these extensions also aids the magazine in dropping free from the magazine tunnel for rapid and consistent reloads.  This extension is specifically designed for the 9mm 21 round magazine and .40 S&W 18 round magazine.  It adds one to its total capacity for a total of 22 rounds or 9mm or 19 rounds of .40 S&W using the factory spring and follower.  Still fits in a 140mm gauge for competition shooting.

XFIVE, X-VTAC, M17, M18, XFULL, RXP XFULL-Size, XCOMPACT, RXP XCOMPACT, Nitron Full-Size, RXP Full-Size, Nitron Compact, RXP Compact

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