Is it normal that the bullet damage are lower in CSDM? I've noticed that when I'm using the m4a1, it would take me 4 to 5 shots most of the time to kill someone. Usually it would be 3 or 4 shots most of the time without CSDM. Is this normal?
You're imagining things. Older versions of CSDM had poor implementations of FFA mode, where shooting teammates had dampened damage. But that was fixed in CSDM 2.1.