Piercing/explosive is a bad combination.
doesn't the hades already do that?
No it does fire and piercing damage, fire can hurt hull pretty good but its no where near as destructive as explosive
Actually, Fire has a 1.3 modifier to hull, while Explosive has a 1.4, so they're actually REALLY close. But Fire also has 1.5 on balloon, and 0.8 on Armor, whereas Explosive has 0.25 Balloon, and 0.3 Armor. So in truth, Fire is actually MORE POWERFUL than Explosive.
That said, Piercing/Explosive =/= harassment. If you wanted a harassment gun, you'd probably want Impact or Flechette, maybe Shatter, as THOSE are the harassment traits. Impact less so though, as it IS the most powerful trait in the game, even if it has some seriously annoying harassment potential in the knockback.