The M134-GAU19b Hybrid is a Heavy machine gun. When compared to the XM556 Microgun,it benefits from a significantly increased rate of fire, but slightly inferior range, minimum damage and damage multipliers to the limbs. It also takes less time to overheat, making it less suitable to longer, sustained bursts; however, it is faster to cool down. These characteristics make it more suitable for shorter, more accurate bursts, but less so for suppressing fire and engaging multiple targets at a time.
SED weapons have inverted spread. It starts at its maximum spread and each consecutive shot thereafter lowers the current spread, until it reaches the spread minimum. In other words, each shot improves the accuracy of the next shot until it reaches maximum accuracy.