Well, on paper, MCH doesn't look that bad A Ninja's basic combo of Spinning Edge (150), Gust Slash (200), and Aeolian Edge (320) has a total potency of 670. For MCH we have Split Shot (168), Slug Shot (216), and Clean Shot (240) plus three turret attacks of 94 damage would give us a total potency of 906. If you're using ammo, that increases to 966 potency total, which is massive and the reason why they added proc chance. The proc chance should keep us about even with other jobs for basic combo damage. We also have a really strong DoT in Lead Shot.

So the question is, what is wrong with the rest of the class that it causes low damage? Is it the mediocre 5% damage increase from Hot Shot? Are the parsers really wrong? Is there a bug? It's hard to really play this class "wrong" as outside of the buff phase, there isn't much to it other than using the combo, refreshing buffs, and using OGCD abilities like Head Graze, Gauss Round, Ricochet and both reloads when they're up.