The AKM is an effective close to medium range assault rifle which can be found in all military loot spawns. It is more powerful than any of the other AK variants, but also much louder. It will kill any zombie with a single shot to the body.
It is the only AK with zeroing capabilities and can be zeroed up to 800m. By default, you can press Page Up and Page Down to adjust the zeroing on the AKM.