Ragnarok.Bleublood said:
»It may be because of having to reapply wind maneuvers to keep the Drum Magazine going as well as the Turbo Charger. The loss in DPS from having to do maneuvers is what I am guessing it has to be. But that's just a guess :P
Sylow talked about barrage turbine which easy damage every 3 min.. dps does get rocked with spamming maneuvers which is why barrage turbine which only has to be focused on once every 3 min with 1 maneuver in between mobs is an awesome attatchment.
Full ranger frame (not valor head sharpshot body) can use barrage turbine, turbo charger(if you have puppet meleeing too), and drum magazine. There isn't any reason that barrage turbine should't be used