So far, the machine gun, we have M249 something weapon, but I just wonder where’s minigun going? isn’t this weapon a heavy weapon?
I did like build the minigun on my car.
Miniguns are aircraft weapons and there are no planes in cata just yet.
I like the “Just yet” 
I so hope we get planes that we can build using the same vehicle construction screen as cars 
There IS a minigun (sort of) in the game, the RM360.
Or I assume it is, since it has five rotary barrels.
Manportable miniguns in riflecaliber are, alas, things of fiction.
(Though a assaultcannon to be used with power armour would be much appriciated)
I’d like to see secondary ammo on weapons (like compressed air for flamethrowers, pneumonics) before a minigun shows up. Although I guess you could always power it off UPS if it’s mounted and you don’t hook a battery into the frame.
edit ; forgot to say, of course I think it should be mounted-only like the M2. It’d be silly otherwise.
double edit ; since the minigun uses .308 and has a stupidly high rate of fire, making it the slightest bit usable without severely overstocking .308 hunting rifle ammo would be challenging. Although if it goes in I expect the devs to leave it just as ridiculously impractical as it’d be irl.
There is currently a PR for a M134 Minigun to be added already. Just go to github and vote for it. And also Miniguns are not airplane specific weaponry. People mount them on vehicles ranging from SUV’S to Hummers and military Humvee’s. Even Miniguns that shoot .50cal. The Gau-18 being one example can be mounted on vehicles. So it wouldn’t be outside the realm of possibility to find a Gau-18 to mount on your vehicle in a Bunker or Military outpost.
The only Minigun that I have seen that is an airplane weapon only is the Gau-8 Avenger on the A10 Thunderbolt which shoots 30MM Explosive ammunition. And the main reason it can only used on that plane is because the gun itself is about the size of the entire plane, not to mention the gun and the plane need each other to be effective and efficient.
And yes, the balance point for the minigun is also it’s good side, it has a burst size of 100… 100 rounds of high-quality ammo every time you fire it.
For the M134, and probably most miniguns, spin-up time could possibly be implemented as a balancing feature in the future.
This does make me want a crank-powered gattling gun to fight zombies now though.