As others have noted, the correct term is magazine, not
clip.

Second, you guys left out the part where the moron painted the
tip of the gun orange, which is usually used to mark
realistic-looking fake guns.

Third, this paragraph:

marching around a national park in camo with a gun with
a nearly foot-long barrel and a full 30-round ammo clip across your
chest

is sensationalist, ignorant ninnyism. Most firearms of that type
of 16-18″ barrels. This particular firearm was designed to get
around the National Firearms Act of 1934*, which regulated
short-barreled rifles. Because of the seriously messed up gun laws,
you cannot take a rifle and make its barrel shorter than 16″, but
if you take a new reciever that has never been in a rifle
configuration and build it so that it has a less than-16″ barrel
and don’t put a buttstock on it, you can call it a pistol and it
will still be legal, despite it essentially being the same exact
thing.

*The NFA was originally intended to ban pistols as well, but
they couldn’t get that included. This makes the ban on
short-barreled rifles and shotguns completely and utterly idiotic,
but for some reason its still around.