You'd hope that riflemen wouldn't spray and pray but it always happens. As for the squad gun debate, the spraying increases exponentially with the squad guns so it all evens itself out.
Making a rule for it is a bad idea, just one more thing for the whiners to phony pony about on the field and yell out - which ruins our realistic experience. When was the last time somebody screamed in a real battle "You aren't supposed to shoot full auto!" It's bad enough they call each other's hits.