Springer Precision

140mm Magazine Extension for Sig Sauer P320 9/40


Springer Precision 140mm extended capacity basepads for Sig Sauer P320/P250 9/40 are CNC machined from aluminum and hard anodized for a long service life. This lengthens the magazine and adds rounds to your magazine. More rounds can be added if you choose the Grams follower options. The unique locking mechanism allows a very solid attachment with a simple backing out of the discrete set screw. They fit the USPSA 140mm magazine gauge. The unique attachment design provides a low profile, sleek design that is very stable and easy to remove.

Installation instructions
2020 version Installation Instructions

*We include a 1/16 hex driver that makes installation and removal a breeze. Up to 23 9mm and 20 40. cal rounds with the extra capacity follower kit. 

1.41 oz

Custom engraved and custom colors are non-returnable.

New version no longer requires modification to the mag tube. Includes a more durable screw.

*Not designed specifically for the 21rd 9mm/18rd .40 factory mags, please see SP0218 for a basepad for those mags if you want them to fit the USPSA Guage for 140mm.

*Not compatible with flanges that fold into the magazine body(P250, P320 Subcompact 12rd).**

**Disclaimer: As with all competition geared changes, always make sure you test and check your gear before you take it to a competition setting.  With 140mm/170mm magazine configurations especially, check the magazine in a USPSA 140mm/170mm gauge to make sure it fits.  With mass produced items like magazines, sometimes they can vary slightly from one to the next, often in the magazine lips that connect with the magazine extension/basepad.

Due to design variations, Springer Precision cannot guarantee compatibility with any other manufacturer’s aftermarket magwell, unless otherwise specified. Please call us with any questions.

Current stock: 0

Bulk Pricing:

  • Buy 6 or above and get $3.75 off

Custom Name Engraving +$5
Numbering +$1
1.41 Ounces