In real-life, a minigun is essentially a scaled-down Gatling Gun, firing smaller cartridges (i.e., something you'd use in a regular infantry rifle).

It's also a go-to weapon for characters who desire more Dakka in a fairly large package.

It may or may not weigh 200 kg, fire custom-tooled cartridges at 10,000 rounds per minute and cost $400,000 to fire for 12 seconds.