I have used it . . .
You walk, fire 2 ERLL and maybe the Gauss depending on the THN- so at most a +2. Walk the next turn doing the same. Walking again, this turn it depends on if you fired the Gauss the previous two turns or not- if you did, you swap out to a ERLL, Gauss, LRM and cool. If not you walk until you reach that heat point, either having fired the Gauss or not.
The Orion IIC pilot is throwing 20-45 damage potentially a turn . . . and if you need to, you can mash the big button outside of 9 hexes and get 55 with IIRC a -1/+1 penalty for the next turn where you can cool enough with proper weapon selection.