This build feels good, and has worked great in ESO, I'll test against lvl 185 Nox and Heavy gunner later. Recently I've noticed Nox seem to die faster to headshots than Heavy Gunners so I'm going to start testing my builds against both.
Typical viral Slash build but focuses a little more on the secondary fires forced Impact procs making Internal Bleeding perfect for this weapon. Paired with the multi-shot slash procs won't be a problem, and with this much fire rate the secondary fire will actually be nice and responsive. The primary fire will work just fine procing slash as well though, just weaker bleeds.