Corrosion: Get 20 or more consecutive kills without getting hit 2 times.
You must get 20 or more consecutive kills (in a row kills) without getting hit 10 times across all camos.
Sunder: Get 3 or more critical hit kills rapidly 25 times.
Cartographer: Get 3 or more critical hit kills rapidly 20 times.
Forecast: Get 3 or more critical hit kills rapidly 15 times.
Gunrunner: Get 3 or more critical hit kills rapidly 10 times.
Acidic: Get 3 or more critical hit kills rapidly 5 times.
You must get 3 or more critical hit kills rapidly 25 times across all camos.
Rising Tiger: Get 10 kills rapidly 10 times.
Blue Tiger: Get 10 kills rapidly 8 times.
Scavenger: Get 10 kills rapidly 4 times.
You must get 10 kills rapidly a total of 10 times across all camos. You must get a total of 15 Elite Zombie (Mini-Boss Zombies such as the Megaton) kills across all camos.
Chemical: 2,500 kills while Pack-A-Punched.
Drench: 1,500 kills while Pack-A-Punched.
Downfall: 750 kills while Pack-A-Punched.
Degeneration: 250 kills while Pack-A-Punched.
Extortion: 50 kills while Pack-A-Punched.
You must get a total of 2,500 kills with a Pack-A-Punched variant of the weapon across all camos. You must get a total of 2,500 critical kills (headshot kills) across all camos.