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Image showing different shotgun gauges: 10 gauge, 12 gauge, 16 gauge, 20 gauge, 28 gauge, .410 bore

Various shotgun gauges

Courtesy of Federal Ammunition

With so many kinds of firearms and types of ammunition, it’s not always easy to match the proper ammunition to your firearm correctly—but getting it right is critical. If you match the wrong ammunition to your gun, you can cause an explosion, injuring or possibly killing yourself and any bystanders.

To match the proper ammunition to your shotgun correctly:

  • Read the gauge designations on the side of the barrel. Match that barrel stamp designation exactly.
  • Carefully read the information on the lid of the ammunition box and on the head stamp on the ammunition. With shotgun ammunition, always check both the gauge and the shell length, and whether it’s a magnum load, to ensure it matches the data on the barrel.
  • Finally, match the proper gauge and length of shotshell, on the ammunition box and the ammunition head stamp to the barrel stamp before you shoot.
The rear of the shotgun barrel is marked with the gauge and the length of the chamber: 12 GA for 2 3/4 or shorter shells

The rear of the shotgun barrel should be marked with the gauge and the length of the chamber.

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