A bolter is a firearm commonly associated with the Imperial Space Marines of the Warhammer 40,000 setting. Crew-served heavy bolters are also used as support weapons in the Imperial Guard, and the Orks have similar weapons, as well.
Bolter weapons come in a variety of sizes, ranging from pistols to vehicle-mounted heavy weapons, but their operating principles are all similar. A bolter launches self-propelled rounds with armor-piercing tips. The bolt shell contains an explosive charge and a detonator that detects when the shell is surrounded by matter dense enough to be living tissue, causing it to explode inside the target. A variety of alternative warheads are available for special purposes, such as incendiaries and flechette rounds.