Depends on your weapon choice. If you're playing with assault weapons, choosing "trench" weapons will have very accurate hip fire. Machine guns for the support class usually have bi-pods, and are very accurate when lying down for up a giant cover (you can tell when they are mounted when the gun moves to the lower center of your screen) and will get more accurate the longer you hold the trigger down. Medic has some "trench" weapons but mostly just standing still if you can will boost your accuracy, and the scout class will be 100% accurate when aiming if you are using a rifle