A musket is a muzzle-loaed, smoothbore long gun, which is intended to be fired from the shoulder. The date of origin of muskets remains unknown, but they are mentioned in Chinese military books such as Huo Long Jing as early as the late 14th century. Muskets were primarily designed for use by infantry. Improved with the introduction of rifling around 1800, muzzle loading rifled muskets (of the kind common during the Crimean War) became obsolete by the late 19th century, as cartridge breechloading repeaters superseded them. However, rifled muskets were the most common weapon used up until the late 1870s. Typical musket calibres ranged from 12 mm to 20 mm (.50 to .80 inches). Depending on the type and calibre, it could hit a man's torso at up to 200 m (218 yards), though it was only reliably accurate to about 60 m (70 yards). A soldier primarily armed with a musket had the designation musketman or musketeer.