page_title: Gauge (firearms)
section_title: Sizes in use
hierarchical_section_title: Gauge (firearms) / Sizes in use
caption_attribution_description: English: Shotgun shell comparison (left to right): .410, 28 gauge, 20 gauge, 12 gauge
context_page_description: The gauge of a firearm is a unit of measurement used to express the inner diameter of the barrel.
  Gauge is determined from the weight of a solid sphere of lead that will fit the bore of the firearm and is expressed as the multiplicative inverse of the sphere's weight as a fraction of a pound, e.g., a one-twelfth pound lead ball fits a 12-gauge bore. Thus there are twelve 12-gauge balls per pound, etc. The term is related to the measurement of cannon, which were also measured by the weight of their iron round shot; an 8-pounder would fire an 8 lb ball.
  Gauge is commonly used today in reference to shotguns, though historically it was also used in large double rifles, which were made in sizes up to 2 bore during their heyday in the 1880s, being originally loaded with black powder cartridges. These very large rifles, sometimes called "elephant guns", were intended for use in Africa and Asia for hunting game.
  Gauge is abbreviated "ga.", "ga", or "G".
context_section_description: The most common size is 12 gauge, with up to 50% of the overall shotgun market in the United States. The 20-gauge shotgun is the next most popular size being favored by shooters  uncomfortable with the weight and recoil of a 12-gauge gun, and is popular for upland game hunting. The next most popular sizes are 28 gauge and .410 bore. Both the 10 gauge and 16 gauge, while less commonplace, are still available in the United States.
  Shotguns and shells exceeding 10 gauge, such as the 8 and 4 gauge, are rather rarely manufactured and only a few makers of the otherwise large market of shotgun, rifle and ammo makers across the United States still produce them. Shells are usually black powder paper cartridges as opposed to the plastic or wax cartridge and smokeless powder of today.
  The 11, 15, 18, 2, and 3-gauge shells are rarest of all; owners of these types of rare shotguns will usually have their ammunition custom loaded by a specialist in rare and custom bores. The 14 gauge has not been loaded in the United States since the early 1900s, although the 2+ inch hull is still made in France. The very small 24 and 32 gauges are still produced and used in some European and South American countries. Punt guns are rarely encountered.
  Also seen in limited numbers are smoothbore firearms in calibers smaller than .360 such as .22 Long Rifle (UK No.1 bore) and 9mm Flobert rimfire (UK No.3 bore), designed for short range pest control and garden guns. The No.2 bore (7 mm) has long been obsolete. All three of these rimfires are available in shot and BB-cap.
caption: left-to-right: .410, 28ga, 20ga, 12ga.
exif: {"Image Make": "Canon", "Image Model": "Canon PowerShot S5 IS", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "GIMP 2.10.12", "Image DateTime": "2019:10:12 01:46:52", "Image HostComputer": "Mac OS X 10.6.4", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "240", "Thumbnail ImageWidth": "256", "Thumbnail ImageLength": "194", "Thumbnail BitsPerSample": "[8, 8, 8]", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail PhotometricInterpretation": "6", "Thumbnail SamplesPerPixel": "3", "Thumbnail JPEGInterchangeFormat": "3254", "Thumbnail JPEGInterchangeFormatLength": "10104", "EXIF ExposureTime": "1/100", "EXIF FNumber": "7/2", "EXIF ISOSpeedRatings": "200", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2010:09:29 18:58:12", "EXIF DateTimeDigitized": "2010:09:29 18:58:12", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "5", "EXIF ShutterSpeedValue": "213/32", "EXIF ApertureValue": "29/8", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "23/8", "EXIF MeteringMode": "Pattern", "EXIF Flash": "Flash fired, compulsory flash mode, red-eye reduction mode", "EXIF FocalLength": "6", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "3264", "EXIF ExifImageLength": "1832", "EXIF FocalPlaneXResolution": "43520/3", "EXIF FocalPlaneYResolution": "1832000/169", "EXIF FocalPlaneResolutionUnit": "2", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "1", "EXIF SceneCaptureType": "Standard"}