In international arms control, small arms are man-portable firearms that shoot kinetic projectiles, including handguns (revolvers and pistols) and individual-operated long guns such as rifles and carbines, shotguns, submachine guns, personal defense weapons, and light machine guns. Together with light weapons, which either are team-operated (e.g. heavy machine guns, portable anti-aircraft guns) or shoot explosive warheads (hand-held or underslung grenade launchers, recoilless rifles, rocket-propelled grenades, shoulder-launched missiles, portable anti-tank guns, anti-aircraft and anti-tank missile systems, mortars of caliber less than 100 mm), they comprise the Small Arms and Light Weapons (SALW) protocol.
According to the United Nations: "Since weapons in this class are capable of being carried, if a small arm, by one person or, if a light arm, by two or more people, a pack animal or a light vehicle, they allow for mobile operations where heavy mechanized and air forces are not available or are restricted in their capabilities owing to difficult mountain, jungle or urban terrain."
In the U.S. military, small arms are "man portable, individual, and crew-served weapon systems used mainly against personnel and lightly armored or unarmored equipment". However, in regard to inventory management, the U.S. Army says small arms/light weapons (SA/LW) are: "Handguns, shoulder-fired weapons, light automatic weapons up to and including 12.7 mm machine guns, recoilless rifles up to and including 106 millimetres (4.17 in), mortars up to and including 81 millimetres (3.19 in), man-portable rocket launchers, rifle-/shoulder-fired grenade launchers, and individually operated weapons that are portable or can be fired without special mounts or firing devices and that have potential use in civil disturbances and are vulnerable to theft."
Generally armed forces around the world fixes the calibre (bore) of the arm as the basis for classification as a small arm, which varies from .50 inches (13 mm) to 1 inch (25 mm). Weapons above the defined calibre are classified as cannons.
The world's top small arms manufacturing companies are Browning, Remington, Colt, Ruger, Smith & Wesson, Savage, Mossberg (USA), Heckler & Koch, SIG Sauer, Walther (Germany), Glock, Steyr-Mannlicher (Austria), FN Herstal (Belgium), Beretta (Italy), Norinco (China), Tula Arms and Kalashnikov (Russia), while former top producers were Mauser & Springfield Armory.
Much of the international work to address the illegal arms trade (or arms trafficking) is raised in the United Nations Conference on the Illicit Trade in Small Arms.
In 2013, the Small Arms Survey said that of the 875 million small arms distributed globally, 650 million — almost 75 percent — are in civilian hands. (U.S. civilians account for 270 million of this total.)[a]:39 About 200 million are controlled by armed forces and about 26 million by law enforcement agencies.:102 Gang members hold between 2 and 10 million small arms and armed, non-state actors[b] hold about 1.4 million.:101 Together, the small-arms arsenals of non-state actors and gangs account for 0.4 to 1.3 percent of the global total.:101