Does a minigun require a BFA?
 

Just what the title says. Watched Predator tonight on G4 and began to wonder if an electrically-operated weapon like the minigun needed a BFA to function.

I wouldn't have thought so, since as far as I'm aware no part of the weapon's cycle of function uses any energy from the round. Electrically operated weapons are in a sense manually operated (it's just not you doing the operating), so it'd be like putting a BFA on a pump-action shotgun or bolt-action rifle.

From what I have been able to dig up about the Predator/T2 minigun...No they don't need a BFA to function but they use restricted barrels for safety reasons.

Yep, there is no need for a BFA since the minigun is run by electric motor. However, due the really high rate of fire, the barrels are restricted to create more pressure to ensure that tons of unburnt powder are NOT flying out of the gun. Usually the force required to push bullet down the barrel creates a pressure cooker (as a metaphor) for fully igniting the propellant powder. Much like the cylinders of an Internal combustion engine, the optimal burn rate to force ensures that most if not all powder is converted into energy by the time the bullet leaves the barrel. Any large excess of unconverted energy is a total waste of smokeless powder.

With a minigun, what would be considered a mild irritant with a semi auto rifle, turns into a wind tunnel of hurricane force of unburnt powder flying down range due to the sheer volume of fire - 100 rounds per second. So taking steps to ensure that powder is completely burned off before it exits the barrel is a good safety issue.

Also the blanks used are underpowered, like 1/4 loads.

Imagine the very small recoil from a .308 blank and multiply that by 100. the resistance pushing back against the shooter would be very difficult to control, especially with multiple takes. :)