It’s pretty simple – you’ll need two things:

The first is an MXT Extension Nut to fit your shotgun.

The extension nut is the model-specific component of the MXT kit, which adapts the extension tube to your shotgun.Without this nut, there’s no way to attach your extension tube.

If you don’t see your brand of shotgun listed under one of the options for extension nuts, contact us at for more information — we likely have something that will work!

Second, you’ll need the MXT Shotgun Magazine Extension Tube Kit of the desired capacity.

The extension tube kit contains the extension tube, tube cap, and spring.These components aren’t specific to a particular model of shotgun (though they are caliber specific — we have both 12 and 20 gauge extensions), so any 12 gauge extension will work on any 12 gauge nut.

We offer extensions ranging from +1 through +9, which range from under 4″ to over 20″ in total length, so make sure you reference that handy measurement and dimension chart on the product page so you know exactly what length you want for your particular shotgun and application.

As long as you have both the MXT extension nut and the MXT shotgun magazine extension tube kit, you’ve got all the components needed to install a Nordic extension on your shotgun.

Shoot a 20 gauge shotgun instead of a 12?

Our 20ga selection isn’t as expansive as our 12ga products, but the extensions work the same way. Just grab a 20ga Extension Nut and a 20ga Extension Tube Kit, and you’ll be ready to go.

(Because our 20ga tubes have much higher structural strength, due to their smaller diameter, use of a barrel clamp is not required with any length of extension — we don’t even make a 20ga clamp)

What about barrel clamps?

While it’s a good idea with any extension tube, we strongly recommend use of a barrel clamp with any extension longer than a +4.We have a few different models of barrel clamps, so make sure you check out the information on the individual product pages.

Our extension tubes are strong, but the clamps add durability and stability to the tube, along with providing a great place to mount slings, lights, or other accessories.