Gaming

it costs two hundred thousand dollars to fire this gun... for twelve seconds.

"oops I ran out of money"

Someone on Reddit actually did the math on this 5 years ago.

The scene in Predator where someone holds down the trigger and fires continuously for 45 seconds is actually vaguely possible.

The gun weighs 39 kg or 85 lbs, so it's possible for a soldier to carry it, especially the soldiers in Predator who are shown to be much, much stronger than the average soldier. The ammo used in 45 seconds would weigh 25 kg, so it's still vaguely possible that the soldier could carry it along with the weapon. The volume of ammo wouldn't be that much of an issue. It's under 1000 rounds for 45 seconds of fire, which would fit in a backpack-sized box.

Another big issue is the recoil. On earth, someone experiences 9.8 newtons per kg of mass. We don't know how much Bill Duke weighs, because he's just an actor, but since Jesse Ventura used to be a "wrestler", we know his billed weight of 111 kg in his wrestling days. So, without any gear on he'd be experiencing 1088 N of force from gravity. Add the weight of the minigun and its ammo that's 175 kg, or 1715N.

The recoil generated by the gun is based purely on the rounds it fires. An online calculator puts the recoil impulse at 13.4 Ns of impulse per bullet. From that reddit post, they figured out the minigun in that scene had been slightly slowed down from the normal 2000 rounds per minute (33.3 rounds per second) to only about 20 rounds per second. But, even then, that means the gun would be generating 268N of force. So, just to avoid being moved, someone would have to lean atan(268/1715) = 8.8 or about 10 degrees forward. That may not sound like a lot, but when you're already carrying the equivalent of another person from the weight of the minigun and its ammo, that's a lot of extra force to deal with.

In many games, you can move normally while carrying a minigun, but as soon as you start firing it you slow to a crawl. They actually got that part right. It would be hard to move freely while this thing is shoving you back with such force.

Pro: you're firing 50-100 rounds per second.

Con: you're firing 50-100 rounds per second.

Next thing I know you are going to tell me that punching trees isn't an effective way to collect wood.

Or how flashlights make a little circle of light in otherwise near-total darkness, as opposed to real flashlights which light up a pretty wide area.

For real. Complaining about the realism of a trope sparked by a T-800 ripping the minigun off of a helicopter due to superhuman strength is more than a little silly.

Ohp. Actually, it looks like Castle Wolfenstein did it first. Still, silly.

It would happen too, just not after a handful of seconds.

Miniguns use multiple barrels so that the barrels don't overheat. But then they increase the fire rate significantly. In Vietnam, a common machine gun mounted in the door of a helicopter was the M60 which has one barrel and fires at about 600 rounds per minute. Door mounted miniguns like the M134 have 6 barrels but fire at up to 6000 rounds per minute. So, the barrels would actually overheat even faster than an M60s would at the full rate of fire despite having multiple barrels. Of course, you couldn't actually shoot at 6000 rounds per minute while carrying one of those on foot, the recoil would not be possible to manage.

Yeah also, real life, you’re not shooting 300 m very often. Your rifle may be capable of it, you’re not. With any real effect anyway.

Source: former infantryman

This is sort of how Battlefield, Battlefront, and Helldivers 2 work, but you play as an incoming reinforcement, not someone already on the field.

Doom 2016 has a pretty quick heat up on its gatling though i dont recall if it was 5 seconds.

Left for Dead 2's minimum has a pretty short lifespan before overheating. Although a single 5 second burst is enough to kill every zombie on the screen

It's more that using multiple barrels keeps any one barrel from heating up too quickly, and it's easier to have multiple barrels than entire firing assemblies.