Achievement is tied to the normal progression of the campaign.
Mission 10: Gallant Thief - Max score of 260.
Weapon Challenge:
Up the Ante - Kill 12 enemies with a sub machine gun without reloading. Using a SMG with a high capacity mag, like the P90, will make this challenge easier. It is best that you start this challenge after you pass the point where you have to use the retinal scanner to get into the security room. This will help ensure that you are able to complete the Hands On tactical challenge. On a side note, your gun seems to reload after you plant the beacons, this does not affect you earning this achievement. Completing this challenge will unlock the PP2000.
Tactical Challenges:
Quigley - Kill two enemies with one shot. This is best done when you are planting the beacons for an airstrike. This portion of the mission is after you hack the security system. The best spot to complete this challenge is when you are heading to place the third beacon. There will be two soldiers near a Gaz-66 truck on the other side of a security station. Line up the shot with the silenced rifle you should have brought.
Hands On - Reach the canteen without firing a shot. This challenge starts immediately after the mission begins. To complete this one, you must reach the Canteen(Cafeteria) without shooting anyone. You can use melee kills to eliminate guards that are in your way. This challenge is completed after you reach the retinal scanner for the first time and walk over to the canteen to grab a "friend" to help you get past the scanner.
Secret Service - While playing on Elite, find President Volodin in the prison in less than two minutes. This begins after you ride the lift to the Maximum Security Area. There will be multiple guards to sneak past. Getting into an open firefight will ultimately lead to failure of this challenge. Take the path through the boiler room. You will need to kill 3-4 soldiers that are in your path. Volodin is in the last cell.Completing all tactical challenges will unlock the Grippod attachment.
Once you reach President Volodin, you will earn the achievement 'Special Election'. From here, you still have to reach the extraction point to complete the mission.
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