This build relies on the -10% heat gen quirk coupled with heatgen and coolrun maxed skill nodes, don't even try it without those skills. 40 damage ghosheat-less alpha strike with good AC5 DPS, almost heat stable by firing only the 4xAC5. Focus a component and pop it, simply keep in mind that, even if you can win a staring contest, you have bigger and easier to isolate hitboxes compared to other assaults, so you should never face tank more than 1 opponent at a time, which clearly can't be achieved sometimes due to bad weapon positioning (you have to completely move out of cover when side poking). ALT: remove ammo for a TC1, AMS, or more amor. Drop to 5 ton of ammo for max armor and +1 DHS.
Took be a while to pick up on the velocities of PPC and AC5 being similar (again (since the PPC/AC5/Gauss poptart nerfs)). LPPC are probably more viable, maybe you could even combine a regular and an LPPC. Will try with 2 regulars as well of course, alpha 2 stronk.
3 light ppc's is also an option, but it's still pretty hot: You get 13 heatsinks with either a LE325 or ST300
At the exchange of half a ton of Ammo from @Excalibaard 's version, you can squeeze a little more speed out of it without giving up DHS.