A shell, in a military context, is a projectile whose payload contains an explosive, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military context. A shell can hold a tracer.
Some sectioned shells from the First World War. From left to right: 90 mm shrapnel shell, 120 mm pig iron incendiary shell, 77/14 model – 75 mm high-explosive shell, model 16–75 mm shrapnel shell.
US scientists with a full-scale cut-away model of the W48 155 millimeter nuclear artillery shell, a very small tactical nuclear weapon with an explosive yield equivalent to 72 tons of TNT (0.072 kiloton). It could be fired from any standard 155 mm (6.1 inch) howitzer (e.g., the M114 or M198).
155 mm M107 projectiles. All have fuzes fitted.
The "flying-cloud thunderclap-eruptor" cannon from the Huolongjing
A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found in warfare and sports.
A projectile being fired from an artillery piece
Projectile and cartridge case for the huge World War II Schwerer Gustav artillery piece. Most projectile weapons use the compression or expansion of gases as their motive force.
Ball speeds of 105 miles per hour (169 km/h) have been recorded in baseball.
The Homing Overlay Experiment used a metal fan that was rolled up during launch and expanded during flight. The metal has five times as much destructive power as an explosive warhead of the same weight.