Deadliest weapon in the world is one of 28 Achievements in The Respawnables.
The description says Kill 100 enemies with the Assault rifle
This achievement can be earned after getting 100 kills with assault rifle.
Note that only enemies in the Mission Mode count as enemies.
Enemies in Multiplayer do not work for this Achievement.
The reward for this achievement are 25 Score Points (when achieved during a match).
Tips and Tricks
When using the assault rifle , take it's range and accuracy into account to take out enemies from a good distance away. Do not fear about missing, as this weapon's accuracy will ensure your bullets reach it's set destination.
A good map for getting this achievement is Sand Town .
A detailed strategy about assault rifles can be found here .