User blog comment:FirestormNemesis/WEAPON EFFECTS/@comment-31412506-20170308032745

I'll answer your questions too.

1) They really don't have a difference because they all damage or affects your health/armor

2) Piercing Shot goes through player, for example, a laser spear has a piercing shot

3) Charm damages your health or takes away your health (slowly)

4) A Chain Shot is the firing that passes through multiple players through a trail muitiple times per shot, for example, an electromagnetic cannon.