Sniper Elite V2 Remastered

Note: It is possible to unlock this achievement and You were only supposed to... (20G) in the same playthrough.
 
To play this mission: Single Player > Challenge > The Landwehr Canal. Note that you cannot play this mission in co-op. It is recommended that you select the Welrod in your loadout before attempting this achievement.
 
You can change the difficulty to Custom and it will not void the achievement since this mission is not considered a part of the main campaign. Recommended settings are:
 

• Difficulty: Custom
• Enemy Skill: Rookie
• Ballistic Realism: Simple
• Tactical Assistance: Full

There are five snipers overlooking the command center in this mission. You need 100% stealth in order to eliminate them, so you can only shoot them when the sound is masked. Also, each sniper should be killed with one shot only. If one shot each doesn’t kill them, they will be alerted and thus void the achievement.
 
From your start point, work around to the balcony, eliminating four enemies with the Welrod. Then from the balcony, you can take out the first two snipers positioned at a distance across the courtyard (tag them to make this easier). Next, drop down and head east across the area between the buildings, stealthily taking out two enemies along your way.
 
Enter the building in front of you (you will be on the second floor) and make your way counterclockwise around to the opposite side (there will be a guard patrolling and one sitting in a chair so silently eliminate them). On the eastern side of the building in the southeast corner is the third sniper in the prone position. Approach him while crouching and shoot him with the Welrod. Next, from his position overlooking the courtyard, the fourth sniper is in a building to the right of the command center on the second floor. Tag him first before shooting him.
 
The fifth sniper is in the building directly south of your current location, again in the southeast corner and again on the second floor. Drop down from the building you’re in and make your way to the next building. Enter it, crouch and to the immediate right is a wooden ramp. Climb up it and turn south and you will see the final sniper to take out.
 
It helps if you hold to focus time on the long distance shots as it zooms in slowly, making your shots more accurate.
 
Note: If for any reason a sniper is not in the position described or in the image/video below, they have somehow been alerted and you must restart the mission.