Henning Group's Sig P320 Magazine Extension Kit is perfect for extending your Sig Sauer P320 magazine with 6 more rounds; whether it is 9mm or 40 S&W. It will work on 17-round 9mm, 21-round 9mm, 14 round 40S&W or 18-round 40S&W magazines! They were designed to fit the USPSA gauge for the Limited and Carry Optics divisions. Attached to the factory 17 round magazines extend the overall length to 141.25mm (5.56").
If you are looking for an extension for competition, everyday carry, or law enforcement, these extensions are super easy to install.
You can use the extensions with the factory follower and spring and achieve plus 6 capacity. For competitive shooters (USPSA), we recommend also getting the Grams or Rune follower and springs that make it a little easier to achieve plus 6 for fast reloads. If you add the Grams or Rune follower kit, it replaces the factory follower, spring, and locking plate.
For 9 mm you will increase from 17 rounds to 23 rounds on a standard-length magazine, and from 21 to 27 on an extended-length magazine. For 40 S&W you will increase from 14 rounds to 20 rounds on a standard-length magazine, and from 14 to 20 on an extended-length magazine.
We offer multiple Follower/Spring Kit upgrades
- Rune Tactical 11-coil spring and follower for 17 round factory mags to upgrade to 23/24 + 1 round capacity - $19.95
- MBX Extreme 11-coil spring and follower for 17 round factory mags to upgrade to 24 + 1 round capacity - $19.95
These extensions are designed to work with the Sig Sauer P320 X-Series models (XFIVE Legion, AXG Scorpion, RXP XCOMPACT, XFULL, XCOMPACT, XVTAC, RXP XFull-Size). It will also work with the Wilson Grip Module and other after-market grip models with a flat bottom. If you want to use it with standard P320 grip modules where the back strap comes down, it will require modification of the grip module to allow for relief for our steel detent. This is how the extension is held in place so standard P320 grip modules will need a relief cut into the grip.