Classic .308 bolt guns. Lots on the board will know better than I, but if it is like LE the mission objective and sniper's preferences will determine the rifle.
I'm slowly acquiring parts for a .308 long range build over the next year or two, along the lines of an M40a5 or GA precision HRT rifle. Things like stock and barrel quality, truing the actions, good pillar and glass bedding, and other factors contribute highly to accurate rifles that snipers employ. A good gun in the hands of a marksman will put 5 rounds in one ragged hole at 100 meters.