"That being said, there also appears to be a 40mm M203 grenade launcher attachment on one of the weapons. That, dear reader, is unavailable on the U.S. market – even in Texas."
You can get a 37 MM "Flare launcher" that LOOKS just like an M203
"Both of those grenades commonly use dynamite as its explosive component "
Wrong, they use cast TNT. Dynamite is made with Nitroglycerin, it is to unstable for military use, minor shocks can cause it to go off.
Lame stream media aren't the only ones who need to do some research.