Minigun

"Now *this* is a big-ass machine gun!"

- Louis

The Minigun is a mounted weapon in Left 4 Dead. It is designed for defending intense standoff areas. The Miniguns were presumably left behind by the military, but were abandoned when the Army left or was killed. It has a small wind-up time, but once it starts firing, it becomes one of the best support weapons in the game. The gun is very powerful but can lose its accuracy at longer ranges. It is bolted to the floor so it cannot be moved, only swiveled in a 170° arc in front of the gun. It has infinite ammo but can overheat; this is shown as the Minigun's barrel quickly glows red, as well as the emission of smoke. This smoke also impairs your vision, causing you to have a harder time shooting accurately. However, this is not an imminent signal of the Minigun jamming, as it takes 20 seconds of continuous firing before overheating. In Left 4 Dead 2, the Minigun is replaced by the Heavy Machine Gun (but its sounds are in the game's files, as it is and was meant to be re-used should the original campaigns be ported in the future). Additionally, the Minigun appears in the Left 4 Dead 2 ports of No Mercy (which was simultaneously released with The Sacrifice), Crash Course, Death Toll and Dead Air (Blood Harvest is the only original campaign that does not feature the Minigun). Prior to this, with the exception of No Mercy, the Heavy Machine Gun served as a temporary placeholder for the Minigun in the aforementioned campaigns due to them being in their beta stages.

Locations

 * The Generator room crescendo event in The Subway of the No Mercy campaign.
 * The roof of the room where the radio is located in the Rooftop Finale of the No Mercy campaign.
 * On the back of an Army transport truck at The Alleys crescendo event of the Crash Course campaign.
 * The roof of a storage room in the The Truck Depot Finale of the Crash Course campaign.
 * Pointing toward the failed barricade in Riverside in The Town of the Death Toll campaign. (In Left 4 Dead 2, the Minigun is removed to force players to run to the safe room rather than trying to outlast non-stop hordes)
 * The upstairs porch of the boathouse in the Boathouse Finale of the Death Toll campaign.
 * In front of the fuel pump in the Runway Finale of the Dead Air campaign.

Tactics

 * You can greatly improve your accuracy by holding out a First aid kit, grenade, or pain pills and then aiming as the crosshair will be the same crosshair as the crosshair from the item you're holding. Line up the vertical line with an Infected and fire away. In L4D2 ports of these campaigns, a melee weapon also works.
 * Always have someone covering your back, because without being able to rotate the weapon 360°, you are vulnerable from behind while using it.
 * Aim for the Hordes or Special Infected. Don't bother shooting at the one or two Infected stragglers if, for example, there is a Hunter in clear sight. Your gun can take out enemies the fastest in close quarters. Use it to trim their numbers or take out the big guys. Let your non-Minigun-wielding friends take down the stragglers.
 * When shooting into masses of Infected, keep an eye on where your fellow Survivors are by looking for their colored outlines. There's nothing worse than getting gunned down by your own ally. (Unless easy mode - Where friendly fire doesn't damage anyone)
 * When fighting a Tank, aim for the concrete that he throws at either you or the other Survivors, as it can be destroyed before it lands.
 * The Tank, when controlled by the AI, will go for the Survivor who is manning the Minigun/Heavy Machine Gun. This can be used to the Survivors' advantage if other Survivors are in danger from the Tank at close range, and the Tank needs to be pulled away.
 * Even when no Infected are present, you should constantly tap the fire button (Because unlike Team Fortress, you can't spin the barrel without firing). This will keep the barrel spinning, and eliminate the long wind-up time when a Horde suddenly comes at you.
 * The Minigun also acts as bait for Tanks in co-op mode, allowing someone to distract the Tank with the Minigun, while the teammates pour lead into him.
 * Try not to overheat the gun. This is especially problematic if there are tons of Infected charging and the gun can't fire. The smoke produced can also obscure your vision and make it harder to see both incoming Infected and your own teammates.
 * The Minigun does not have vehicular properties, meaning that Special Infected can still use their abilities on someone using a Minigun.
 * While most people avoid using the Minigun, there's no replacement for it in finales. If a Tank is within range, hop on and open fire; this will most likely take a large portion out of its health if it doesn't kill it outright. Also, note that shooting the Tank continuously with the Minigun will reduce its speed.

Glitches

 * Turning your flashlight on or off while you're using the minigun will cause the flashlight to flicker repeatedly until you dismount (L4D1 only).
 * Like with the Heavy Machine Gun, one may be randomly knocked off of the Minigun in the middle of fire and have some problems getting back on, this is likely because you try to back off the Minigun and USE it at the same time, this may also happen when doing the other way around (using the Minigun then "getting off" it).
 * If there is an oxygen tank, gas can, or propane tank under where you would be standing on the Minigun, you will be above the normal height you would be at, and can aim farther down, but less upward. This counts only for non-picked up pickups (e.g. those on Crash Course 1 minigun near Howitzer).
 * Previously there was an exploit where players could repeatedly shove the Minigun from behind, jump on it and be launched forwards a great distance (this allowing them to bypass one Crescendo Event in particular or die from falling). This was patched later on.
 * When the player is getting charged by a Charger while using the Minigun, the player will still be in aiming animation, rather begin knocked to the ground, even when charged off the building. However, should the player dismount the Minigun after the player is getting charged and the Charger is killed, the animation of standing up will play.