- As with the rocket launcher and BFG9000, the first-person chaingun sprite is slightly too large for the screen, and can only be viewed with a level or resource editor.
- The target of chaingun fire often appears to turn and shuffle rapidly in place, due to the continual interruption of its sprite sequences. Doom's instruction manual refers to this motion as "the chaingun cha-cha."
- The chaingun first appeared in the Doom press release beta. Its graphic was slightly different, in that the tips of the barrels did not extend past the barrel band.
- Wolfenstein 3D, the game id Software released immediately before Doom, included a similar chaingun. However, it was a blue color, and had a significantly higher rate of fire, functioning as the ultimate weapon in-game; the submachine gun was more in-line statwise to the Chaingun.
- If the Doom chaingun is associated with real weaponry, it is a Gatling-style weapon with rotating barrels similar to a minigun. An actual chain gun only has a single barrel and uses an electric motor to drive a chain connected to the bolt assembly, moving it back and forth to load, fire, extract, and eject ammo cartridges.
- Unlike most real-world gatling-style weapons such as miniguns, the Doom chaingun has a pistol-grip styled handle and trigger group similar to those found on assault rifles or submachine guns, rather than being an infantry-portable minigun seen in the films Predator (1987) and Terminator 2: Judgement Day (1991). As a result of these characteristics, it's implied that the chaingun can be held single-handedly like a pistol by a muscular user (as illustrated by the Heavy Weapon Dude, or by its appearance in the Doom comic) or perhaps held like an assault rifle.
- The weapon's conventional clip-feed, large gray frontal handgrip, and conventional pistol grip imply that it is an assault-rifle type weapon. Due to the fact that conventional ballistic weapons have heat-management issues in the vacuum of space, a rotary-barrel weapon would last significantly longer, which would make it more appealing to space marines than a conventional assault rifle.
- The chaingun first-person sprites imply that the weapon has multiple frontal barrels protruding from its final ring; however, the pickup sprite displays a single barrel protruding past the front ring (as depicted in the Doom comic).
- As with all firearm hitscan attacks, the average damage inflicted per bullet by the player's weapon is slightly higher than that of monsters using equivalent attacks.
- In the Saturn port, the chaingun fires much faster than it normally would.
- In the Game Boy Advance port of Doom II, the weapon fires only one shot at a time, and has a somewhat higher overall rate-of-fire. However, the accuracy of the weapon is significantly lower, due to the fact that the dispersal is cone-shaped rather than fan-shaped, and single shots have the same dispersal as automatic fire.
- While the chaingun does not have a reload animation, it makes sense in this particular case, as opposed to the other traditional firearms. It is implied to be belt-fed due to its name and functionality, and that fact is corroborated by the Heavy Weapons Dude's appearance in Doom II (the weapon's pickup sprite is somewhat ambivalent in this regard; it has what appears to be a clip inserted into the bottom of the weapon, though this could be a box that holds an ammo belt, or even just a foregrip).
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).
- 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.