The rifle, invented in the 15th cent., is a firearm with a grooved, or rifled, bore that imparts a spinning motion to the bullet, giving it greater accuracy. (The principle of rifling the inner surface of the barrel is applied also to artillery.) Rifles first came into widespread practical use in the E United States. Because of its slow rate of fire and its manufacturing cost, the rifle remained relatively unused as a military weapon in Europe. Until the middle of the 19th cent. the musket was the standard small arm.
In the early 19th cent. firearms were revolutionized by the invention of the percussion-cap method of igniting gunpowder. The percussion cap was a small metal capsule, filled with fulminate of mercury, that exploded when struck and fired the gun instantly; it soon replaced the flintlock. Another important advance was the development of gas-expanding bullets, such as the minié and Burton bullets, in the 1840s. In 1855 the United States adopted a new form of firearm called the rifled musket—a gun that looked like a musket, used the minié bullet, had a rifled barrel, was muzzle-loaded, and was fired by percussion caps. It was used by both sides in the U.S. Civil War. Thereafter all small arms became rifled with the exception of the shotgun, a smoothbore firearm designed for short-range firing of either a single slug or a number of small shot. Shotguns are either double-barreled or single-barreled and can be single-shot or repeaters; they are used mainly for hunting.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.