Make Every Bullet Count
Complete a level with 100% accuracy, using only rifles
An easy achievement to miss, but also an easy one to unlock once you've completed the game on your chosen difficulty, To gain this ahievement select Prolog and cadet difficulty.
On Prolog after the cutscene kill the main target, then turn around and make your way to the courtyard, you can either shoot both from up top where there is cover, or you can jump down and shoot them, once you've taken these two guys out make your way to the corner and crawl through the hole in the wall, make your way to the front of the building and take cover in the doorway, move the camera angle so that you can see the guard on the gate, once he's turned around and started to walk back the other way (away from you) walk very slowly towards the back of the damaged vehicle, and then cross the street giving the guys chatting in the street a wide birth, once you make it upstairs you'll see a guard come out of a room on the left, shoot him with your sniper rifle and then make a run to the back room, as soon as you reach the back room you will have to make a choice, either take cover and fight (and make sure you kill all enemies with your sniper rifle), or jump over the wall straight away (as in the vid) and you'll get a cutscene start, soon after you'll get the acheivement / trophy unlock
http://game-play.tv/video/SMYBNRDR6GNS/Sniper-Elite-v2-Make-...