Machinist speaking, and I can say that it's very easy for our DPS to fall to abysmal levels. But, with that in mind, you also have to consider the turrets. I'm not sure if current parsers take them into account, but they're supposed to be used in conjunction with Gauss Barrel to make up for our lack of an auto-attack. The rest just boils down to proper cooldown management. It took me quite a while to see how dreadfully low my own DPS was, so I had to completely rework how I managed my buffs so that every fight didn't take an eternity.