Nordic Components MXT Magazine Extension Kit +5 - High-Capacity Shotgun Upgrade

The Nordic Components MXT Magazine Extension Kit +5 gives your 12-gauge shotgun a genuine capacity boost without breaking the bank or requiring a gunsmith visit. This is a straightforward, affordable way to add five extra rounds to your magazine tube—useful whether you're running clay courses, hunting waterfowl, or just want more ammunition on hand at the range. The kit includes everything you need to get started: the extension tube itself, the correctly matched spring, and an end cap. You'll just need to source the appropriate extension tube nut separately, which threads onto your specific shotgun model.

Built from anodized 6061 aluminum, the MXT extension is engineered for durability and minimal weight penalty. The design incorporates a relief groove that prevents unwanted barrel clamp travel, so your tube stays put after you take the gun apart and reassemble it—a detail that matters if you service your shotgun regularly. The groove sits off-center by design, giving you the flexibility to reverse the tube for slight positioning adjustments if you need fine-tuning for fit. Both ends are machined with matching thread pitch, so the tube itself is reversible if your setup calls for it.

Nordic Components built these kits with real-world shotgun ownership in mind. The +5 configuration works on a broad range of 12-gauge platforms, though fitment specifics depend on your exact shotgun model and barrel length. For Benelli M1 and M2 owners, the +5B variant is engineered for a clean, flush fit on 21-inch barrels. If your shotgun isn't a Benelli, verify your model's compatibility before ordering the nut, since that's the part that locks everything to your gun.

Magazine extension projects are usually simple, but this kit removes guesswork on spring length and component matching—you get the right pieces from the factory. Just confirm which extension tube nut fits your shotgun, order it separately, and you're ready to install.

Key Features

• Adds five rounds to your 12-gauge magazine tube
• Anodized 6061 aluminum construction for strength and corrosion resistance
• Includes extension tube, matched spring, and end cap—everything except the nut
• Relief groove design prevents barrel clamp travel and maintains consistent placement after disassembly
• Off-center groove allows for positioning adjustment via tube reversal
• Reversible tube design with matching thread pitch on both ends
• +5B variant engineered for flush fit on Benelli M1/M2 with 21-inch barrels

Specifications

Frequently Asked Questions

Do I need to buy anything else to install this extension?

Yes. This kit includes the tube, spring, and end cap, but you'll need to purchase the correct Nordic Components extension tube nut separately. The nut is what threads onto your shotgun's magazine tube, so verify your specific shotgun model before ordering to ensure compatibility.

Will the +5 extension fit my shotgun?

The +5 kit is designed for 12-gauge shotguns, but fitment depends on your exact model. Nordic Components offers a +5B variant specifically engineered for flush fit on Benelli M1 and M2 shotguns with 21-inch barrels. For other shotgun platforms, check your model's compatibility with the correct extension tube nut before purchase.

What's the relief groove for?

The relief groove prevents the barrel clamp from shifting during disassembly and reassembly, keeping your extension tube in a consistent, repeatable position. The groove is positioned off-center so you can reverse the tube slightly for minor position adjustments if needed during installation.

Can I reverse the extension tube?

Yes. Both ends of the tube are machined with matching thread pitch, and the off-center relief groove allows the tube to be reversed for positioning adjustments. This design flexibility helps you dial in the fit on your specific shotgun.