Chaingun

The chaingun (also known as "gatling gun") is a rapid-firing, multi-barrelled automatic weapon. It uses the same ammunition as the pistol, and is fed from the player's shared stock of bullets. The Doom chaingun is very resemblant to the Gryazev-Shipunov GSh-6-23 rotary cannon.

Doom 64
In Doom 64, the Chaingun is depicted with longer perforated/vented barrels and a worn blue tone (rather than its Doom counterpart's polished steel appearance). The handle and trigger group is also more similar to those used on real-world minigun-style weapons. Additionally, it has a smaller blue muzzle flash. The pickup sprite has a somewhat rusty appearance as well. When fired at a consistant rate, the screen will jerk up and down rapidly (though this is only a visual effect that does not mess with the gun's fire or aim at all).

Trivia

 * The weapon's classic first-person sprites are based off of a toy minigun called the Tootsietoy Ol' Painless.
 * The weapon was originally an assault rifle or submachine gun-type weapon in the Doom alpha, but was redesigned into a slow-firing rotary-barrel Gatling gun to give it immediate visual differentiation from other weapons, as well as to give it its own distinct style.
 * The chaingun’s hud sprites in the Atari Jaguar port of Wolfenstein 3D are based on Doom’s.