II.

Guns

A gun is a cannon that fires projectiles from a long tube (known as the barrel) at high velocity in a low, flat trajectory. The projectile usually carries a charge that explodes when it hits its target. The barrel of a gun may have spiralled grooves in its bore; the process of adding these grooves is called rifling. Rifling improves the stability of a projectile in flight, making its trajectory more accurate. Some guns use ammunition that can pierce armour. Guns are widely used on warships, armoured combat vehicles, and tanks.

The first artillery guns fired simple projectiles that did not explode. Later guns fired ammunition that released shards of metal, called shrapnel, in the air. These early guns were loaded from the front (known as the muzzle) of the barrel. Modern guns are loaded from the side, which increases the speed and ease by which they may be fired.