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  • Home
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  • Magazine Extensions
  • Mossberg 590 Series Magazine Extension
  • Mossberg 590, 535, & 835 Series Mag Tube MK II
  • Mossberg 590 Series Magazine Extension
  • Mossberg 590 Series Magazine Extension
  • Mossberg 590, 535, & 835 Series Mag Tube MK II Mossberg 590 Series Magazine Extension Mossberg 590 Series Magazine Extension

    Mossberg 590 Series Magazine Extension

    S&J Hardware

    (You save )
    (7 reviews) Write a Review
    SKU:
    MOSS-590
    Width:
    8.00 (cm)
    Height:
    8.00 (cm)
    Depth:
    8.00 (cm)
    License Required:
    Non-Restricted

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    • Overview
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    Product Description

    **TO AVOID SHIPPING DELAYS, PLEASE INPUT YOUR PAL NUMBER, DATE OF BIRTH, AND EXPIRY DATE IN THE INFORMATION FORM WHEN PURCHASING ONLINE.**

    Will fit Mossberg 590, 535, and 835 shotguns. Not compatible with the Mossberg Shockwave; it will fit, but won't allow for an extra round.

    CNC machined from 4140 steel.

    Finished product will be Cerakoted in the following colours:

    • Graphite Black
    • OD Green
    • Patriot Brown
    • Silver (Best match for electroless nickel)

    Comes with:

    • 3 Position Sling Plate
    • C Clip (to install sling plate)
    • 1 Million Cycle Magazine Tube Spring
    • No Jam Follower - Type 3

    Overall length:

    • +1 - 2.25 inches
    • +2 - 4.5 inches and is designed for pre-2017 590/590a1 or 835

    Made in Canada.


    Compatibility: *Likely not compatible with any clamp designed for use with a tube made of aluminum, or having a plastic sleeve covering. These tubes tend to be a little thicker in diameter.

    Product Videos

    Custom Field

    License Required Non-Restricted

    Product Reviews

    Write a Review

    Write a Review

    ×
    Mossberg 590, 535, & 835 Series Mag Tube MK II
    S&J Hardware
    Mossberg 590 Series Magazine Extension

    7 Reviews Hide Reviews Show Reviews

    • 5
      Excellent.

      Posted by Andrew Singleton on 18th Oct 2025

      Im in the UK, so our 590 can only have 24” or longer barrels. This +2 extension fits flush with the 24” barrel, a perfect fit, and so far has function flawlessly with the original spring. Also quick thank you to SJ for super fast delivery to the UK, mossberg bits are surprisingly hard/expensive to get hold of over here!

    • 5
      Fits Great!

      Posted by David Stanik on 1st Jun 2025

      This fits good for my 590 Mossberg. Fun shooting an additional shell. Took me a bit to understand how long the new spring should be.

    • 5
      Excellent product

      Posted by Mark on 17th May 2025

      Fit and finish is perfect! I used the one round extension on a mossberg 590 breacher and it cleared no problem.

    • 5
      Mossberg 590 mag tube mk II plus 1

      Posted by Steve on 4th Feb 2024

      Excellent bit of kit. Arrived in UK within 10 days of placing order. Fits perfectly on my Mossberg Mariner and adds that extra 1 round capacity that is needed in IPSC competition. Major benefit is that it is a single piece, where other extensions comprise a nut and a tube and possibly an end cap as well (so three threads that might unscrew in use, where the S&J only has what amounts to a replacement factory end cap that includes a built in extension, so it stays put once attached. No barrel clamp needed). I would recommend it.

    • 5
      Mossberg 835 UltiMag

      Posted by Aston Mello on 4th Nov 2023

      Excellent product! Thankfully my Canadian brothers to the north have the part I needed. Thank you !

    • 5
      Mag Tube + 1 Extension - Mossberg 590

      Posted by Robert Zeppieri on 29th Jan 2023

      Quick shipping, Excellent quality, Looks fantastic. Only tested with snap caps so far but everything seems to be working great and I love the HiViz follower. Very happy with this purchase and service from S & J Hardware. Will definitely be purchasing from them again.

    • 5
      Mossberg plus 1 extension

      Posted by Chris on 30th Dec 2022

      No complaints. Quality feels excellent, installation was a breeze. Haven't had the gun to the range yet, and won't get the chance for a while, but feels nice and snug. Recommended.

    ×

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