On the contrary, there were repeating rifles in existence at least 100 years before the Revolutionary war. The Kalthoff and Lorenzoni designs were basically primitive lever actions that allowed their user to fire a shot every second or two. Both of these were invented in the 1600s, and while not widespread due to cost, enough were built that there are surviving examples today. Can't say for sure, but I would expect that the founders were aware of them.
As for 800 rounds per minute from a semi-automatic, I have my doubts.