MG4

The MG4 is based on a real-life weapon with the same name. It has a relatively high rate of fire and a not-so-low amount of damage per shot. IMHO, it is one of the top medium-range weapon, and can match far-range weapons. (I've used the high rate of fire, high ammo capacity and high stability of the weapon to my advantage, killing snipers in Outpost and Urban.)

Origin and Update
It has high rate of fire and an OP amount of damage at first. After a few updates, Lucas has settled for a high rate of fire and lower damage (but still advantageous).

Usage
Given that it is a heavy machine gun, you will run normally but when you scope in, you will be noticeably slower then normal. Again, you use this gun as it is - a machine gun, use it to suppress people down, and when they are behind cover, try shooting through the cover as they hunker down. Or, you can run with this as an assault rifle, with it's high rate of fire and relatively low recoil.