Actually, politicians routinely played that confusion in the leadup to the original AWB. Whenever they talked about "assault weapons," the news would cut to footage of a machine gun being fired.Much like trying to explain that the bad, scary rifles you see on the average gun shop shelf are NOT Full Auto!
From the horse's mouth:
The weapons' menacing looks, coupled with the public's confusion over fully automatic machine guns versus semi-automatic assault weapons—anything that looks like a machine gun is assumed to be a machine gun—can only increase the chance of public support for restrictions on these weapons.