I suggest getting it as soon as you arrive at the third map, it makes the rest of the game a walk in the park) (SIDENOTE: The best silenced sniper rifle in the game, the Dragoon, is located northweast of the third map, in a question mark map point, right next to a high priority target who is inside of a system of caves.
The trophy is awarded for getting all sniper rifles, and this can be obtainable by doing all the sidemissions and main missions, and also finding them in some places in the map which have the question mark. This trophy is not glitched, but it can SCREW YOUR SAVEGAME.
