(5 customer reviews)

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Velocity Mag Extensions are back! IMPORTANT - PLEASE READ:

Some of you are aware we are based in Tumwater, Washington. A state which passed the Unconstitutional Bill 5078 which bans the sale and possession of “High Capacity Magazines”

This Bill also effects our ability to sell one of our top selling accessories, the Velocity Mag Extension in Washington State.

As of July 1st 2022:

Killer Innovations stopped making these and selling them.

As of August 25th 2023:

Killer Innovations will be re-releasing this beloved product for out of state sales only!

Welcome back! Thank you for your patience and support.


Our new Velocity Mag Extensions “Enhanced Grip Feature” cuts will change the way you reload. E.G.F. cuts provide an aggressive serrated lip that give the shooter ultimate grip and angularity control while feeding the mag into the pistol. E.G.F. cuts are located at the bottom-front and sides of the mag extension, so however you prefer to grab your mag for a reload, a perfect grip is always there. The Velocity Mag Extension was designed with strength and durability in mind. Our testing proved the mag extension could survive massive abuse, being repeatedly dropped from 6’ onto concrete without a single failure. Cleaning your mag is made easy with our toolless floor plate removal. Just depress the retaining pin and slide the floorplate out. It’s that easy!

Mag Extension for Sig P320 Specs:

  • Material: 6061 T6 Aluminum
  • Finish: Anodize
  • Dims: 1.84″ x 1.20″ x 1.514″
  • Weight: 1.472
  • Compatible with: All P320 X Series Grip Modules
  • +5 rounds


Mag Extenson for Sig P320 Installation Instructions

*Due to some rolling changes in designs made by Sig, there is a chance that our parts may not be compatible with your specific gun, despite being noted as compatible with the variation.  Please test fit parts CAREFULLY to avoid damage, in case of incompatibility.  We will return or exchange undamaged parts.

Due to differences in metal composition and finishing processes, Killer Innovations cannot guarantee exact color matches among our accessory items.  For more information please see our detailed explanation.


*Killer Innovations is not responsible if you purchase an item you cannot legally possess in your state, county, or city. Some states, including but not limited to: Washington, California, Illinois, New York, Massachusetts, Connecticut, Hawaii, and New Jersey, restrict the sale and ownership of certain firearms and/or firearm parts and accessories. It is your responsibility to know your state and local laws before making a purchase at Killer Innovations.


  1. commander (verified owner)

    love the look but didnt come with a replacement spring for the price others come with one.

  2. Zack Rosenquest

    Hello! Thank you for the support. In our testing the Sig mag springs come from the factory slightly overpowered. We found including a plus powered spring was not needed. This saves the user some money also by not adding an unnecessary expense.

  3. Jose Tiscareno (verified owner)

    i wish the coating was stronger. was able to scratch down to bare Aluminum very easily. (accidentally) installation was easy. i am still definitely going to buy another one.

  4. Eric Ventura (verified owner)

    These are hands down my favorite mag extensions. I like the aggressive look, they are well machined, and the finish is perfect! The blue is deep and lucious!

    Please, please, please, make these for the P320 XTEN!! I took measurements and it’s so very close, just a few tweaks and you’d have fitment for the 10mm/45ACP Magazines!

  5. Ed Rutter (verified owner)

    Great Extensions. Will Be Buying More in the Future. So Glad that you were able to Start up Production AGAIN. You All Need to Move to Missouri where you can Be Free from All of the BS in your State!

  6. Clay Jones (verified owner)

    These extensions are just awesome. Work on both of my 320’s flawlessly. The look of these extensions is badass. Well built and beefy! Not a fan of the magwell that I purchased tho. Put it on and it was just too cheesy looking. I opted to keep the original on.

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