I propose my favorite ARC 5W build. 280 Firepower The first Heavy or Assaut Mech who crosses his path will not like at all!!! After launched all the Rockets (220 dmg), it's possible to fight honorably with the MRM60. No heat probleme with this build, except during the Rocket launch phases. Always active the overheat engage. Use the asimetric build to tank damage until the destruction of the right side torso. If you think you don't have enought ammo for MRM, you can downgrade the RLE20 to RLE15 for 2 tonnes of it or remove Heatsinks. 1 Group : MRM60 2 Group : 2xRLE20 Right arm 3 Group : 2xRLE20 Left arm 4 Group : 3xRLE10
that's actually really scary ^^ With Light Engines the heat efficiency plummets once you lose an ST, so I prefer to build it symmetrically and torso twist a bit more or in the additional ammo variant you suggested:
Hilariously powerful and HOT build. Ripped countless heavies and lights with that first alpha strike from this build. Might shutdown for a prolonged time but WORTH IT haha.