thumb|BB pistol with cartridges and BBs

A BB gun is a type of air gun firing 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 in 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 (because lead is more malleable and exerts less wear on the rifling).

The term "BB gun" is frequently used colloquially 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 damage or mechanical failure within the pellet gun.

History

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 because of the loose tolerances in shotshells. The largest 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 called birdshot.

Multiple-pump pneumatic guns are also common. Many pneumatic pellet guns provide the ability to use BBs as a cheaper alternative to lead shot. Some of these guns have rifled barrels, but the slightly undersized BBs do not swage in the barrel, so the rifling does not impart a significant spin. These are the types of guns that will benefit most from using precision lead BB shot. Pneumatic BB guns can also attain higher velocities than traditional spring-piston types.

The last common type of power for BB guns is compressed gas, most commonly the Powerlet cartridges. The powerlet is a disposable metal gas cylinder containing of compressed carbon dioxide, with a self-contained valve to release the CO<sub>2</sub> which expands to propel the BB. These are primarily used in BB pistols, and are capable of rapid firing unlike spring-piston or pneumatic types. A typical CO<sub>2</sub> BB pistol uses a spring-loaded magazine to feed BBs, and a double-action trigger mechanism to chamber a BB and cock the hammer. However some guns (either to stay true to the original gun or to make the trigger pull easier) do have a single-action trigger. Either type of gun may also have blowback action, where CO<sub>2</sub> will push the slide back in addition to firing a BB. When firing, the hammer strikes an internal valve linked to the CO<sub>2</sub> source, which releases a measured amount of CO<sub>2</sub> gas to fire the BB; this also gives it realistic recoil and muzzle report features. Many CO<sub>2</sub> BB guns are patterned after popular firearms such as the Colt M1911, and can be used for training as well as recreation.

Some gas-powered BB guns use a larger source of gas, and provide machine gun-like fire. These types, most notably the Shooting Star Tommy Gun (originally known as the Feltman) are commonly found at carnivals. The MacGlashan BB Gun was used to train antiaircraft gunners in the United States Army Air Corps and United States Navy during World War II. A popular commercial model was the Larc M-19, which used 1 pound (454 g) canisters of Freon-12 refrigerant. These types have very simple operating mechanisms, based on a venturi pump. The gas is released in a constant stream, and this is used to suck the BBs up into the barrel at rates as high as 3600 rounds per minute.

Safety

160px|thumb|BB gun injury showing a 4.5 mm steel BB that penetrated the middle finger on the left hand

BB guns can shoot faster than , but are often less powerful than a conventional pellet airgun. Pellet airguns have the ability to fire considerably faster, even beyond . Although claims are often exaggerated, a few airguns can actually fire a standard 0.177 caliber lead pellet faster than , but these are generally not BB-firing guns.

A BB with a velocity of only has skin-piercing capability, and a velocity reaching can fracture bone. This is potentially lethal, and this potential increases with velocity, but also rapidly decreases with distance. The effective penetrating range of a BB gun with a muzzle velocity of is approximately . A person wearing jeans at this distance would not sustain serious injury. However, even at this distance a BB still might penetrate bare skin, and even if not, could leave a severe and painful bruise. The maximum range of a BB gun in the range is 100–200 metres approximately, provided the muzzle is elevated to the optimum angle.

Steel BBs are prone to ricochet off hard surfaces such as brick, concrete, metal, or wood end grain. Unlike lead pellets, which usually flatten and absorb energy upon impact, a BB bouncing off a hard surface can retain a large portion of its initial energy, and could easily cause serious eye damage. Wearing eye protection is essential when shooting BBs at these materials, more so than when shooting lead pellets.

Quick Kill training

The U.S. Army trained recruits in Quick Kill techniques using Daisy Model 99 BB guns to improve soldiers using their weapons in the Vietnam War from 1967 to 1973. The technique was developed for the Army by Bobby Lamar "Lucky" McDaniel and Mike Jennings.

BB guns are often regulated as a typical air gun. Air gun laws vary widely by local jurisdiction.

See also

  • Airsoft gun
  • Paintball marker
  • List of air guns
  • Pellet (air gun)

References

  • US Patent