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Concept
BB gun
Résumé
A BB gun is a type of air gun designed to shoot metallic spherical projectiles called BBs (not to be confused with similar-looking bearing balls), which are approximately the same size as BB-size lead birdshot used on shotguns ( in diameter). Modern BB guns usually have a smoothbore barrel with a caliber, and use steel balls that measure in diameter and in weight, usually zinc- or copper-plated for corrosion resistance. Some manufacturers still make the slightly larger traditional lead balls that weigh around , which are generally intended for use in rifled barrels (due to lead having better malleability and exerting less wear on riflings).
The term "BB gun" is frequently used incorrectly to describe airsoft guns, which shoot plastic pellets (also often referred to as "BBs") that are larger (usually in diameter) but much less dense than metal BBs, and have significantly lower ballistic performance. The term is also sometimes used to describe a pellet gun, which shoots diabolo-shaped (not spherical) lead projectiles at higher power and velocity. Although some BB guns can also shoot pellets, the reverse situation is not true: steel BB balls have greater stiffness and are not meant to be shot from pellet guns, whose barrels are typically rifled and thus can get stuck (similar to a squib load in firearms) and lead to a damage or mechanical failure within the pellet gun.
The term BB originated from the nomenclature of the size of lead shots used in a smoothbore shotgun. Size "BB" shots were nominally , but tended to vary considerably in size due to the loose tolerances in shotshells. The highest size shotgun pellet commonly used was named 00 or double ought and was used for hunting deer and thus called buckshot, while the smaller BB-sized shot was typically used to shoot small/medium-sized game birds and therefore was a birdshot.
In 1886, the Markham Air Rifle Company in Plymouth, Michigan produced the first wooden-construct spring-piston air rifle design as a youth training gun, and used the BB-size birdshot as the chosen ammunition.
Source officielle
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