I think you want to use cover to get closer since the straight trajectory of the projectile makes it hard to hit people who are hiding. They also have reasonable downtime, the weapon can be quite ink hungry. Once you get close enough, rush them while dodging as much as possible as they'll have to hit multiple committal shots to kill you.
It's a very high skill floor weapon
you need a lot of practice with both the main weapon and the special to make them work at a decent level, but once you get it you REALLY get it.
I prefer to use zipcaster as either a distraction tool, or as in the clip above: hit them once and then slam into them for a huge burst of damage