Strafer Gott said:
You have to hit it first to damage it. Please, don't even consider full auto, as you are not going to have that option here.
At a 100m I find it hard to believe that most if not all those that have posted to this thread couldn't hit a man sized target (in semi-auto) with a AK47 or a SKS, I know I can.
While 200m plus the AR has the advantage over the AK. How often in a combat situation does a rifleman actually engage a target over 200m or even 100m? In urban setting it's normally only the distance across a street or less, in rual areas you might get 200m (plus) shots but with everyone practicing on static targets chances are very small that you would hit anything due to lack of experience of leading a moving target.
So what is really the advantage of one over the other? It will depend strictly on your situation.