20-gauge shotgun
Smoothbore/rifled shotgun caliber
From Wikipedia, the free encyclopedia
A 20-gauge shotgun, also known as 20 bore or 20 gauge, is a type of smoothbore shotgun. Twenty-gauge shotguns have a bore diameter of .615 in (15.6 mm), while a 12-gauge shotgun has a bore diameter of .729 in (18.5 mm).[2] Twelve-gauge and 20-gauge shotguns are the most popular gauges in the United States, where ownership of firearms is common.[3][4] The 20-gauge is popular among upland game hunters, target shooters, and skeet shooters in many areas of the world.[4]
23⁄4" (70 mm)
3" (76.2 mm)
| 20-gauge/20-bore | ||||||||||||||||||||||||
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Three 23⁄4" 20-gauge shells (right) loaded with #71⁄2 birdshot | ||||||||||||||||||||||||
| Type | Shotgun | |||||||||||||||||||||||
| Place of origin | United Kingdom | |||||||||||||||||||||||
| Production history | ||||||||||||||||||||||||
| Manufacturer | Various | |||||||||||||||||||||||
| Variants | 21⁄2" (63.5 mm) 23⁄4" (70 mm) 3" (76.2 mm) | |||||||||||||||||||||||
| Specifications | ||||||||||||||||||||||||
| Case type | Rimmed, straight | |||||||||||||||||||||||
| Bullet diameter | .615 in (15.6 mm) | |||||||||||||||||||||||
| Shoulder diameter | .684 in (17.4 mm) | |||||||||||||||||||||||
| Base diameter | .697 in (17.7 mm) | |||||||||||||||||||||||
| Rim diameter | .766 in (19.5 mm) | |||||||||||||||||||||||
| Rim thickness | .0484 in (1.23 mm) | |||||||||||||||||||||||
| Case length | 2.76 in (70 mm) | |||||||||||||||||||||||
| Primer type | Shotshell primer | |||||||||||||||||||||||
| Maximum pressure | 12,000 psi (83 MPa)[1] | |||||||||||||||||||||||
| Ballistic performance | ||||||||||||||||||||||||
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Description
Twenty lead balls of a 20-gauge shotgun bore weigh one pound, while just 12 lead balls of a 12-gauge shotgun bore weigh the same.[2] A 20-gauge shotgun is more suitable for hunting certain types of game or for some hunters because it may have less felt recoil than an identical shotgun in a larger gauge,[5] and guns may be smaller and weigh less, though this has changed since the introduction of the 3-inch magnum shotshell.[3]
Regarding the yellow body tube color that 20-gauge ammunition usually has, it has been reserved in SAAMI documentation saying "SAAMI has reserved yellow for 20 gauge ammunition" "This ammunition shall have a body tube that is primarily yellow" "Yellow shall not be used for any other gauge/bore shotshell body" "No other recommendations are made as to the color of service body tubes for other gauges/bores"[6] This color designation may be designed to aid in identifying 20-gauge shells. A 20 ga shell, if mixed in with 12-gauge shells, will enter the chamber and lodge inside the bore at the end of the chamber. The result is catastrophic if a 12 ga shell is loaded and fired behind the lodged 20 ga shell.[7]
Specifications
20-gauge shotguns are especially suitable for hunting game birds such as quail, grouse, and mallards when using lead-free birdshot. A 20-gauge buckshot load would most commonly be utilized in close- to mid-range self-defense scenarios.[citation needed] While slug loads are ballistically less accurate than rounds used in rifles, powerful, high-grain slug loads can provide improved ballistics for hunting deer when paired with a rifled barrel.[8]
Recoil
On average, 20-gauge rounds will produce less muzzle energy than 12-gauge rounds, resulting in reduced perceived recoil. However, there are many variables that affect perceived recoil, including gun weight, action type, stock pattern, shot weight, shell size, etc.[9][10] There may be little to no difference between the two when using target ammunition. Loads for waterfowl will tend to produce more felt recoil in a 12-gauge shotgun than in a 20, but this may not be the case depending on the gun used.[9] Full-power 20-gauge shells fired from a light 5 lb (2.3 kg) gun will have more felt recoil than those fired from a heavy 7 lb (3.2 kg) gun.[11] For a fair comparison, two identical shotguns, one in 12 and one in 20, with identical ammunition (other than gauge) have to be compared. In those cases, the 12-gauge does generate more recoil energy than the 20.[9][12]