BB guns are a type of air gun designed to shoot projectiles named BBs 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 balls 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.

One of the most famous BB guns is the Red Ryder BB Gun by Daisy Outdoor Products, modeled after the western Winchester rifle. First introduced in 1938, the BB gun became an iconic American toy, and is still in production today.

The term "BB" originated from the size of steel ball used in a Shot Shell of the same size. BB shot was nominally 0.180 inches (4.57 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 their BB gun bore diameter to .175 inches (4.45 mm), and began to market precision-made lead shot specifically for their BB guns. They called this "air rifle shot", but the "BB" name was already well established, and everyone continued calling the guns "BB guns" and the shot "BB shot" or just "BBs".

A gun is a muzzle or breech-loaded projectile-firing weapon. There are various definitions depending on the nation and branch of service. A "gun" may be distinguished from other firearms in being a crew-served weapon such as a howitzer or mortar, as opposed to a small arm like a rifle or pistol, but there are exceptions, such as the U.S. Air Force's GUU5/P. At one time, land-based artillery tubes were called cannon and sea-based naval cannon were called guns. The term "gun" evolved into a generic term for any tube-launched projectile-firing weapon used by sailors, including boarding parties and marines.

In modern parlance, a gun is a projectile weapon using a hollow, tubular barrel with a closed end — the breech — as the means of directing the projectile (as well as other purposes, for example stabilizing the projectile's trajectory, aiming, as an expansion chamber for propellant, etc.), and firing in a generally flat trajectory.

The term "gun" has also taken on a more generic meaning, by which it has come to refer to any one of a number of trigger-initiated, hand-held, and hand-directed implements, especially with an extending bore, which thereby resemble the class of weapon in either form or concept. Examples of this usage include staple gun, nail gun, glue gun, grease gun. Occasionally, this tendency is ironically reversed, such as the case of the American M3 submachine gun which carries the nickname "Grease Gun".

Steve-O (born Stephen Gilchrist Glover; June 13, 1974) is an English-born American stunt performer and television personality. His entertainment career is mostly centered around his performance stunts on the American TV series, Jackass, and accompanying movies.

Steve-O was born in London, England. His mother, Donna Gay (née Wauthier), was Canadian, and his father, Richard Glover, was American. His paternal grandfather was English and his maternal step-grandfather was voice-over announcer Wayne Howell. His family was based in England for many years due to his father's presidency of the South American division of Pepsi-Cola. During his childhood he lived in a number of countries, including Canada, Brazil, Venezuela, and Uganda, where he spent two years before returning to the United States.

His first hometown in the United States was Darien, Connecticut, at the age of four. He moved to Miami two years later. When he was nine his family returned to London where Steve-O attended the American School in London in St. John's Wood for four years of school. As a child, he was an avid Mötley Crüe fan. In 1987, Motley was playing at Maple Leaf Gardens in Toronto, Canada where his family was living in at the time. He phoned every hotel within and outside the vicinity until he found the name that the band usually checked in under, manager Doc McGhee. He did not speak to Doc, but rather his brother Scott, but McGhee was so impressed with the resolve of Steve O to meet Motley that he brought him out for their show, let him meet them, and hang with them backstage, as told in Tommy Lee's autobiography.