In Diner Turned, get a kill with each primary weapon in a Public Match.
In Turned you get a new weapon for every kill. There are a total of 6 weapons you need to get kills with making these achievement fairly easy to unlock. Sometimes it will take several kills to receive a new weapon but be persistent and you'll get this achievement. Unless you are playing against a group of inexperienced players, this achievement will be quite difficult.
If you get a group of friends to join you (by searching over and over again until you meet in the same lobby), you can knock this out very easily.
- Chicom CQB