The AK-FU is a fully automatic weapon in Sunset Overdrive. It acts exactly like an actual AK-47: fast firing, accurate, and easy to use. During the development cycle, the AK-FU was actually one of the first weapons the player would acquire, and featured heavily during the tutorials and early levels. In the game proper, this role has been split between the High Fidelity and the Dirty Harry, with this gun acquired late in the game.
In most games, the AK-FU would have been your Jack of All Trades weapon, and indeed, was in earlier stages of development, but this role has been relegated to the Roman Candle. As of now, the gun is best used when you are facing a small number of tough foes like the Fizzco Bots and need to keep your distance.
Against regular OD, the AK-FU is a fantastic waste of time and ammunition. Being able to lock only to one target at a time, and consuming bullets at a rapid pace, you're better off using the High Fidelity which was specifically designed for this, or a second automatic weapon, the Roman Candle.
Special OD Edit
Against all varieties of special OD, the AK-FU is a good weapon for whittling them down when you can't get a bead on them with more specialised guns, or have simply run out of ammunition. The rapid firing accuracy will deal consistent if unimpressive damage, great if you're focusing on repositioning or traversing rather than aiming.
Feel free to use either the Dirty Harry or the AK-FU against Scabs, both are equally effective depending on play style and player preference, though obviously, the FU has the advantage in large groups if not the stopping power and ammo efficiency.
Fizzco Bots Edit
The AK-FU is a solid choice against Fizzco's robotic minions. Already extremely durable and coming in small groups, with large hit boxes, this gun is great for just whittling down their health while focusing more on dodging and avoiding getting shot at.
The abbreviation FU means Fuck You.