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BB gun

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Steel BBs

BB guns are a type of air gun designed to fire spherical projectiles, called BBs, usually from a smoothbore barrel. BB guns have a .177 inches (4.425 mm) bore diameter, and most modern BBs are steel, plated with zinc or copper to resist corrosion. Some manufacters also make lead BBs, which are generally intended for use in rifled barrels.

Airsoft guns are also commonly referred to as BB guns, as they also shoot spherical projectiles through a smoothbore barrel. However, airsoft "BBs" are 6mm in diameter (.24 inches), made of plastic or other non-metallic materials, and are designed specifically to be non-lethal.

Safety

While most BB guns are very low powered, suitable only for plinking or target shooting, BB guns are capable of killing humans and pets in rare cases. Steel BBs are also very prone to ricochet, especially off hard surfaces such as brick or concrete. Eye protection is even more essential when shooting BBs than when shooting lead pellets, since a bouncing BB may retain a very large portion of its initial energy, and could easily cause serious eye damage.

History

While it is often stated that "BB" stands for "ball bearing", this is not the case. The original BB guns used the BB sized lead shotgun shot, midway between B and BBB size. BB shot was nominally .180 inches (4.5 mm), but tended to vary considerably in size due to the high allowable tolerances for shotgun shell use. Around 1900, Daisy, one of the earliest makers of BB guns, changed the bore diameter to .175 inches (4.375 mm), and began to market precision made lead shot specifically for BB guns. They called this "air rifle shot", but the "BB" name was already well established, so everyone kept calling the guns "BB guns" and the shot "BB shot" or just "BBs".

In the 1920s, Daisy began to hear reports of BB gun users salvaging scrap steel ball bearings for use in their guns; a number of guns came in for repair with split barrels, from oversized bearings being forced down the barrel. The bearing manufacturer, American Ball Company, quickly seized on this as an opportunity, and started to market .175 inch steel air rifle shot specifically for BB guns. This quickly led to an exclusive marketing agreement with Daisy, as precision ground steel BBs were cheaper to make than precision lead BBs. The lighter steel BBs also provided better velocities than lead, which made the BB guns shoot flatter and more accurately at the short ranges where they were effective. By 1939, Daisy had acquired American Ball Company, which it used to produce its own steel BBs. Since Daisy was the dominant player in the BB gun market, other makers followed suit, matching Daisy's bore diameter and switching to steel BBs.

Operation

BB guns can use any of the operating mechanisms used for air guns; see the powerplant technology section of the air gun article. However, due to the limited accuracy and range inherent in the BB gun, only the simpler and less expensive mechanisms are generally used.

Since nearly all BBs used today are steel, it is common to find BB guns that use magnets in their loading mechanisms. Since the BB is too hard to be swaged to the bore size, magnets are often used to hold the BB at the rear of the barrel--otherwise, the BB would simply roll out of the barrel were held at a downwards angle.

The traditional, and still most common powerplant for BB guns is the spring piston type, usually patterend after a lever action rifle. This was the first type of BB gun, and still dominates the inexpensive youth BB gun market. These models generally have very low velocities, a result of the weak springs used to keep cocking efforts low. These guns often have huge ammunition capacities; one of Daisy's early models held 1000 BBs. The ammunition is gravity fed, so the gun must be held at the proper angle when cocked to load the ammunition.

Multi-pump pneumatic guns are also common--many youth oriented pneumatic pellet guns provide the ability to use BBs as a cheaper alternative to lead shot. These guns have rifled barrels, but the hard, slightly undersized BBs don't swage or obturate to fit the barrel, so the rifling may not impart a significant spin. These are the type of guns that will benefit most from using precision lead BB shot, but the additional cost of such lead shot removes most of the motivation for use. The pneumatic BB gun attains much higher velocities than the traditional spring piston types. One interesting use of a pneumatic BB gun is in the calibration of ballistic gelatin, which is done by measuring the penetration of a steel BB at a velocity of about 600 ft/s (180 m/s).

The last common type of power for BB guns is pre-compressed gas, most commonly the 12 gram CO2 powerlet. The powerlet, invented by Crosman, is a disposable bottle containing 12 grams of liquid carbon dioxide, which evaporates to form a gas to propel the BB. These are primarily used in pistol BB guns, and unlike spring-piston or pneumatic types, these are capable of rapid fire. A typical CO2 BB pistol uses a spring-loaded magazine to feed BBs, and a double action trigger mechanism to chamber a BB and cock the hammer. The hammer strikes a valve hooked to the CO2 source, which releases a measured amount of CO2 gas to fire the BB. Velocities of CO2 powered BB pistols are moderate, and drop off as the temperature in the CO2 source drops, due to changes in the vapor pressure. Many CO2 BB guns are patterned after popular firearms, 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 are commonly found at carnivals, and have also been used to train antiaircraft gunners. A popular commercial model was the Larc M-19, which ran off 1 pound (454 g) canisters of Freon refrigerant. These types have very simple operating mechanisms, based on a venturi system. The gas is released in a constant stream, and this is used to suck the BBs up into the barrel at a very high rate--advertisements for the Larc M-19 claimed a rate of fire of 3000 rounds per minute.

Ammunition

In addition to the traditional steel or lead balls, there are a number of types of special ammunition that can be used in appropriate types of BB guns, general breech loading models with tip-up barrels.

Airgun pellets of the correct diameter, .177 caliber, (4.425 mm), can be loaded into many BB guns. Since airgun pellets are often made in a fairly stable, front-heavy design, even a smoothbore barrel can fire them with a reasonable degree of accuracy for short distances.

Another type of ammunition used in smooth bore air guns is the dart, which consists of a small, pointed metal body with a string tassel on the end. Darts are used only in low-powered guns for indoor target practice, and can be used in place of hand-thrown darts in a game of darts. The original air gun darts were used in very accurate, handmade, target guns used in formal competition in late 19th and early 20th Century Germany. Modern darts come in an additional form, the bolt (after crossbow bolts), which uses plastic fins in place of the tassels.

A standard copper coated steel .177 cal BB usually usually weighs about 5.3gr (About 1/3 of a gram.) A lead airgun pellet may be about 7.9 gr (about 1/2 of a gram.)

Competition use

While most BB guns are used only for informal plinking, it is possible to shoot competitively with a BB gun. The National Rifle Association youth shooting program has classifications for smoothbore BB guns, open from ages 8 to 15, and these classes are popular with youth groups such as Boy Scouts and 4H. BB guns are generally shot at a distance of 5 meters (5 yards 1 foot 8 inches). To hit the tiny 10 ring on the standard 5 m BB gun target, which is about the size of a BB, requires a very accurate BB gun and very consistent BBs. The dominant BB gun used is the spring piston Daisy model 499, a specially made competition BB gun that Daisy, and many shooters, claim is the world's most accurate BB gun. When used with the Number 515 precision ground BBs, made specially for the 499, the combination allows amazingly tight groups for a BB gun. The 499 retails for around US$75.

BB guns are regulated in the same manner as air guns. In countries where there is a maximum velocity or muzzle energy at which point an airgun is treated like a firearm (such as in Canada or the United Kingdom), BB guns are often not powerful enough to be considered firearms. See the legal issues section of the airgun article for more information.

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