Master Sniper Achievement
Uncover Wolff's planThis is story related and cannot be missed. This can be earned on any difficulty.
During Mission 7, 'Karlshorst Command Post', after fighting your way into the command post, work your way down the hallway, carefully eliminating any enemy you come across. At the end of the hallway, turn right and there will be an officer who is carrying Wolff’s plans. Kill him and search his body to unlock the achievement.