Sig P320 9mm, Capacity +1,  Performance Spring and Follower



Not available for shipment to CA, CO, CT, D.C., HI, MD, MA, NJ, NY, WA, VT
  • +1 Capacity
  • Black
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Must be used with Warne +5 Sig Mag Extension
Steel Spring with Polymer Follower
Designed and MADE IN USA

The Warne® Performance Spring/Follower for the Sig Sauer P320 17 round magazine is designed to enhance magazine capacity by allowing an extra round to be loaded when using the USPSA legal Warne +5 magazine extension for a total of 23 rounds. Extra capacity cannot be guaranteed on other aftermarket extensions or factory base plates.

Fits Sig P320, 9mm 17 round factory magazines with Warne +5 mag extension for a total of 23 round capacity. Magazine & extension NOT included.

WARNING & DISCLAIMER: Not for sale, possession, or use in any jurisdiction where the Warne® Handgun Magazine Extensions would violate applicable law or expand a firearm magazine capacity beyond the applicable limit. It is the responsibility of purchaser and user of the Warne® Handgun Magazine Extensions to know and comply with applicable firearms laws, including magazine capacity limits or modification of firearms. By acquiring Warne® Handgun Magazine Extensions, purchaser represents that Warne® Handgun Magazine Extensions can be lawfully used in purchaser’s state or local jurisdiction. Warne specifically disclaims all liability related to any possession, transfer (sale, gift, exchange or otherwise), use, or modification of this product that violates or would cause violation of applicable law.  Warne is not responsible for any harm or damage from misuse or modification of this product or from malfunction due to modification of any goods by use of this product contrary to specific Warne provided instructions and specifications.

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Part Number:
Steel & Polymer
Sig P320, 9mm 17 Round Factory Magazines

Installation Instructions

To install the Warne® Magazine extension, remove the factory base pad and retaining clip. Please verify magazine is removed from firearm and is empty.
  • Remove base plate or existing extension. Remove existing spring/follower. Insert Warne Performance Spring/Follower and install Warne +5 Sig P320 magazine extension.
  • Verify that the tail of the spring has seated in the bottom of the extension by sliding the extension away from the mag body slightly and looking down into the bottom of the extension.
  • Slide the magazine extension all the way on until the spring pops into the extension cavity. Install the screw and washer and firmly tighten. The washer will compress as the screw is tightened, so be careful to not overtighten the screw.
  • Load and unload the magazine 3 times to allow the spring to break in.