I've scanned the book three times now and can't find this answer. It's entirely possible I might just be missing it.
Is it possible to fire beyond the listed Range for a weapon? If yes, what is the penalty?
The description of "Range" under weapon qualities tells me to read the Range Bands rules on page 208/9. The Range Band rules don't have any rules about weapon ranges.
There is some implication that there is a penalty, but I'm not seeing anything concrete.
If I were to make a call, I'd say it would be "add one Difficulty Die per move action it would take to get to the weapon's listed range". So a Medium range weapon firing at Extreme range would be +4 difficulty dice (the worst example I could think of).
Players will be players, so they will always want to take a shot beyond the listed range of a weapon if the situation calls for it, so I am not inclined to say "you just can't do that".