Should I be using the m4a4 or the m4a1s?

Long range - m4a1s

Close range - m4a4

M4a4 in close range has faster rate of fire but its less accurate due to worse recoil than m4a1s. Also its good for wallbanging. m4a1s is good if you want reduced recoil and you engage enemies on long range aka long dust2, nuke yard, train t main and so on. It's all preference. Some people prefer m4a4 due to bigger magazine and faster rate of fire and if they are holding close part of site. Others prefer m4a1s for reduced recoil and more accuracy on long ranges. Whatever floats people boat.