"The founding fathers never thought we'd have assault rifles."

The founding fathers of the U.S.A., who by the way were essentially what we would call today "libertarians," were not stupid. They were in fact revolutionaries. Of course they foresaw weapons technology increasing to then-unfathomable levels. Already in their lifetime there were machines being developed that could fire more rapidly than a musket, which took between 20 seconds and one minute to load and fire one musket ball.

They also still had things like cannons and explosives, which at the time were used by pirates and other criminal gangs (such as governments) to wreak all kind of havoc.

Yet somehow, the constitution had no language in regards to types of "arms" that citizens were guaranteed the right to own.

How vague. "Arms."

What a wide array of dangerous things to grant its citizens the right to own, from a organization intent on the organization of society in a hierarchical way based on a monopoly on the use of violence. I wonder why they were so vague.

Could it be because the founders of the U.S. government (the most harmful terrorist organization in the world today) were ironically right about the danger of corrupt governments, and by not heeding their historic lesson, your risk of being in a FEMA camp in a couple years increases greatly?

Naaaaaaah. Keep listening to the media, like those people in that movie with the guy who finds the sunglasses...