The M16 has some better qualities then ak47 for example its way more accurate then AK-47, m16 has better bullet power and the fire of the bullets goes in circling motion which maximize the damage to the target in like 70% more.The m16 can easy deal with water and rainy weather condition but does not support desert weather and can get jammed pretty easy if some send gets to it...
There are many versions for the m16 which reduce the weight of the original rifle and make it lighter to allow advantage of speed in built areas