[TalonDJ]

Nope. They make 'em out of plastic, in case terrorists ever bring plastic guns aboard. (No, I am not making this up.) And one guy who tests screeners said that making the dummy gun out of metal would "make it too easy to find."
Your FAA and TSA at work...

This is why I approach the topic from the assumption that the badguys will get on armed. If that is preventable (I have yet to see it) it might change my stance.

[Poohbah]

This is why I approach the topic from the assumption that the badguys will get on armed. If that is preventable (I have yet to see it) it might change my stance.

With a proper screening protocol, they won't. When was the last time you heard of someone bringing a gun onto an El Al flight?

The problem is that the "guns" used in the test cases are NOT guns. They are not a couple pounds of ferrous metal. They are intended to see if the crews can detect the infamous (and nonexistent) "plastic guns" that Sarah Brady was soiling her Depends over back in the late 1980s.

When the guy testing the screener screwed up and stuck a REAL gun into the bag, it got caught immediately...and the tester was searched, and they found the "test gun" in his holster.