This is probably one of the most cost-effective builds I ever tried out. Stock Engine, replace Ferro-Fibrous to light ferro, upgrade to Endo-steel. It is actually hotter than it looks, especially if you double tap in hotter maps... Just avoid double tapping anymore if you get the "heat level critical" warning. 800 potential damage pre-skills, plus those UAC10 are everything you need to hammer your opponents both at short and medium ranges and are quite good at pinpointing despite shooting two pellets per "trigger-pull".
