Firearm whose barrel is rifled (i.e., has spiral grooves cut inside it to give a spin to the projectile). Though usually applied to a weapon fired from the shoulder, the name can also refer to a rifled cannon. Rifled firearms date to at least the 15th century, when it was discovered that imparting a spin to the bullet improved its range and accuracy. The earliest muzzle-loading rifles were more difficult to load than smoothbore muskets, but the invention of metallic cartridges made possible the development of breech-loading mechanisms. Bolt-action rifles, which use a manually operated cylinder to drive the cartridge into the rifle's chamber, are the most common type for hunting. See alsoassault rifle.