BB guns are a type of air gun designed to shoot projectiles called BB after the Birdshot pellet of approximately the same size. These projectiles are usually spherical but can also be pointed; those are usually used for bird hunting. Modern day BB guns usually have a smoothbore barrel, with a bore diameter and caliber of 0.177 inches (4.5 mm). BB for modern day BB guns are usually steel, plated either with zinc or copper to resist corrosion, and measure 0.171 to 0.173 inches (4.34 mm to 4.39 mm) in diameter. Some manufacturers also still make lead Ball bearings of slightly larger diameter and which are generally intended for use in rifled BB gun barrels, as were formerly used in BB guns. Some Asian companies make plastic BBs for recreation. BB gun barrels are .177 caliber.
Airsoft guns are also commonly referred to as BB guns or pellet guns, as they also shoot spherical projectiles through a smoothbore barrel. However, airsoft "BBs" are 6 mm in diameter (0.24 inches), made of plastic or other non-metallic materials, and are designed specifically to be non-lethal.
BB guns are not to be confused with airsoft guns, the latter of which are considerably lower energy and possess far less damage potential to humans. Note that a lead/steel .177 projectile fired above 350 fps has skin piercing capability, and as would be expected, the potential can exist for delivering a fatal injury; this potential increases with increasing velocity.
As a note, steel BBs are also very prone to ricochet, especially off of hard surfaces such as brick or concrete. Eye protection is essential when shooting BBs, more so than when shooting lead pellets, since a bouncing BB retains a very large portion of its initial energy (pellets usually flatten and absorb energy), and could easily cause serious eye damage up to and including blindness.
In the 1920s, Daisy began to receive 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 steel balls being forced down the barrel. The bearing manufacturer, American Ball Company, quickly seized on this as a marketing opportunity, and started to market 0.171 to 0.173 inch diameter steel air rifle shot specifically for BB guns with a bore diameter and caliber of 0.177 inches. 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 higher velocities than lead BBs, which made new 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 in 0.177 caliber (4.5 mm) measuring 0.171 to 0.173 inches in diameter.
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 if it were held at a downward angle.
The traditional, and still most common powerplant for BB guns is the spring piston type, usually patterned after a lever action rifle or a pump action shotgun. The lever action rifle was the first type of BB gun, and still dominates the inexpensive youth BB gun market. The Daisy Model 25 BB gun, modeled after a pump action shotgun with a trombone pump action mechanism, dominated the low price, higher performance market for over 50 years. Lever action models generally have very low velocities, around 275 ft/s, a result of the weak springs used to keep cocking efforts low for use by youths. The Daisy Model 25 BB gun typically achieved the highest velocities of its day, ranging from 375 ft/s to 450 ft/s. Lever action guns often have huge ammunition capacities; one of Daisy's early lever action models held 1000 BBs, in contrast to the Daisy Model 25 which held only 50 BBs. The ammunition in the lever action BB guns is gravity fed, such that the gun must be held at the proper angle when cocked to load the ammunition. The ammunition in the Daisy Model 25, on the other hand, is spring loaded, and no shift in gun angle is required to reload another BB.
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. 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-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 a very high rate, as much as 3600 rounds per minute.
In addition to the traditional steel or lead BBs, there are a number of types of specialty ammunition that can be used. In appropriate types of BB guns, general breech loading models with tip-up barrels.
Air gun pellets of the correct diameter, .177 caliber, (4.5 mm), can be loaded into many BB guns. Since air gun 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.
Copper and/or Zinc coated steel .177 caliber BBs usually weigh between 0.33-0.45 grams (about 1/3 of a gram); this weight depends partly on type; the typical values of common varieties are 0.33g or 0.36g (nominal) for standard weight to 0.45g for heavy variants. (Note: 0.177-inch diam: 0.450 cm: (0.0151*PI) cm^3 times 7.8 g/cm^3 for steel = ~0.372 g). A lead air gun pellet weighs about 7.9 gr (about 1/2 of a gram.)
While most BB guns are used only for informal plinking, it is possible to shoot competitively with a BB gun. The National Rifle open from ages 8 to 15, and these classes are popular with youth groups such as Boy Scouts of America and 4H.
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 1967-1973. The technique was developed for the Army by Bobby Lamar "Lucky" McDaniel and Mike Jennings. The sights were removed from the BB guns for this training.
Chief defends shooting of teen ; Bragdon says BB gun looks like a .45 and 15-year-old told officer he was going to kill her
Sep 30, 2003; A 15-year-old boy fatally shot in the face Saturday by a Spokane police officer was holding a BB gun made to look like a Colt .45...