The AKU-12 is an unlockable carbine in Battlefield 4. It acts very similarly to the AK-12 assault rifle, having less range and accuracy, but having greater hip fire accuracy. It also has a unique feature in which burst fire yields a higher RPM. The recoil is also extremely low, with the gun gently pulling to the right.
The AKU-12 in the killfeed.
The AKU-12 being used in Paracel Storm in IGN's BF4 gameplay demo. Click photo to watch the gameplay.