I'm not familiar with ACC's but I thought they had an aluminum core or something. I have been shooting xx78 super slams and just bought some ICS hunter elites. I was fairly impressed with the carbons until I shot the alums with them. Its just me but I still like the alums and for me they seem to fly faster, straighter. One thing, I'm using a WB deluxe QS model for large alums. It gives me clearance on the alums and plenty on the carbons. I can't see why it would slow the carbons down but it sure seems like something is. I'm still trying them out though so it may change.