How to Make a Mossberg 600AT 12 Gauge Plug

The Mossberg 600AT shotgun fires 12-gauge rounds and was made specifically for certain stores to sell under their own name. This shotgun, now discontinued, is the same as a Mossberg 500. The 600AT came with a factory "plug" installed in the spring of the magazine to limit the number of shells it can hold to three: two in the magazine and one in the chamber. Some states have regulations that require that a shotgun carry no more than three rounds when hunting waterfowl. With the plug removed the shotgun can hold either five or six shells, depending on length of the shells. You can make a plug for the 600AT using a wooden dowel and common tools.

Things You'll Need

  • 1/4" wooden dowel rod
  • Measuring tape or ruler
  • Pencil
  • Hand saw
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Instructions

    • 1

      Measure the dowel to a length of 7.5 inches and mark it with a pencil.

    • 2

      Cut the dowel at the 7.5-inch mark.

    • 3

      Remove the barrel of the shotgun by turning the cap on the end of the magazine.

    • 4

      Drop the 7.5-inch dowel down the back of the magazine, inside the large spring. This will serve as the plug.

    • 5

      Reattach the barrel and tighten the cap on the end of the magazine.