Instructions
Join a domination match. Domination is the best match type when attempting this challenge, because you can post up in the area of the three flags to ensure a steady stream of enemies.
Equip an AUG LMG with a silencer. The AUG has the smallest magazine of the available LMGs. Having a silencer ensures that you won't be seen on the radar while firing.
Camp in an area around one of the three flags. Camping, or hiding in one spot, is important when attempting this challenge. Change your hiding places occasionally throughout the match to ensure you aren't discovered.
Shoot at enemies in short bursts. Firing too many rounds will decrease your accuracy and hurt your chances of unloading all of your rounds without missing.