Here is the full list of all 10 Full Metal Sergeant achievements.
Assign an M.O.D. by the end of the first week.
Don’t assign any M.O.D. until the 10° week.
Acquire the Inspection gold medal.
Acquire the Inspection bronze medal.
Enable ‘Insult Mode’ for all the recruits.
Click on the Sergeant and make him speak to you 3 times.
Pet the dog 3 times.
Finish last in a competition.
Win a competition.
Graduate a class that is entirely Riflemen