Griffen 3-inch Ordnance Rifle
The 3-inch ordnance rifle was the most widely used rifled gun during the war. Rifled heavy guns were a new weapon in the American Civil War where spiral grooves along the inside of the gun barrel spun the shell or shot and enacting gyroscopic force that increased the accuracy of the gun by preventing the shell from rotating along axes other than the axis parallel to the gun barrel.
Invented by John Griffen, the 3-inch ordnance rifle was extremely durable with a wrought iron barrel primarily produced by the Phoenix Iron Company of Phoenixville, Pennsylvania. The gun was also revered for its exceptional accuracy. During the Battle of Atlanta, a Confederate gunner was quoted as saying: "The Yankee three-inch rifle was a dead shot at any distance under a mile. They could hit the end of a flour barrel more often than miss, unless the gunner got rattled."
Like most of the rifled guns in the Civil War, the 3-inch ordnance rifle was muzzle-loaded.