With all this hoopla about new airport security going on, I have been surprised not to hear anything about banning non-metal guns, such as the Glock fiasco afew years back.
Granted making a gun without any metal in it, and that works is probably next to impossible. However could anybody enlighten me on whether Congress ever passed a "plastic gun" law.  If they did what legally is a "plastic gun"?    
I see Kevlar AR lowers for sale, and they technically are firearms, but contain no metal.
I am usually pretty up to date on all firearm laws but after searching the web I can't find a definitive answer.
Just curious.

JBNTEX

The hammer, trigger, sear, pins and springs are still metal, even in a Kevlar lower. Besides, you can't fire it without an upper and there is lots of metal there.

perhaps someone will make a gun with ceramic barrels, hammers, uppers, firing pins and stuff like that... only thing that cant be nonmetal is the ammo... just like that ceramic knife I saw on the web...

we do have a law like that
says something liem must have x amount of metal in it. wish i could rememeber the name of that law but i belive there is one