Agreed, brabazon.
What concerns me, though, is that there is only one line of defence in sutuations like these, and that is the security staff.
If the X-ray machine isn't working properly, or the staff ar not as vigilant as they were yesterday, then the gun gets on board.
It doesn't matter if it was real or whether it was loaded or not. If people believe it is real when it is produced, then your in deep doodoo.
Should carryon baggage be examined twice? Once before the departure lounge and once at the gate?