That mech, my friend, is using a basic General Massive Systems Type-1 assault rifle, even says so on the picture. Come on, a Pilot who doesn't remember the EVEREST's weapon selection?
I appreciate how each revision moves the EVEREST away from it's original slot as the newbie mech that should be abandoned ASAP, to a real option for a serious character.  You can play as a high-level pilot with a million custom mods on a barely recognizable EVEREST without being bad now, compared to the first draft.