Holy shit. You're not even kidding! Check out the definition here. Under the definition, it says that it includes (among other things) anything that is a 'destructive device' as defined here which in turn includes,
any type of weapon...by whatever name known which will, or which may be readily converted to, expel a projectile by the action of an explosive or other propellant, and which has any barrel with a bore of more than one-half inch in diameter...
This is so funny, it's not even funny.
Note: the above links say it's a U.S. Code prelim (i.e. some revisions might happen). But I found similar things here.
The Boston marathon bomber was charged with using WMDs...
There's a lot of background mess in our mental pictures of the world. We try and be accurate on important issues, but a whole lot of the less important stuff we pick up from the media, the movies, and random impressions. And once these impressions are in our mental pictures, they just don't go away - until we find a fact that causes us to say "huh", and reassess.
Here are three facts that have caused that "huh" in me, recently, and completely rearranged minor parts of my mental map. I'm sharing them here, because that experience is a valuable one.