Charging up the shot, it'll cause some hella kickback. It's 6 frames as is, but I might add more so charge up isn't instantaneous, of course if that isn't a problem.
Once it reaches max charging, it loops between the last two frames until you fire a shot, or jump in which the shot will be retained if possible, otherwise it'd just cancel.
EDIT: What do you guys think so far? Going to start on the kickback.