I don't know NEAR as much about guns as you do but it seems to me that there has been nothing NEW in the last fifty years or so. At least nothing that has made it to the commercial market.
Why is that I wonder?
I had high hopes for metal storm..but it never happened.
I mean I have book knowledge, but very limited practical knowledge (which is really what matters). Yeah it has been stale for a long time. I think the next revolution in the industry will probably be related to ammunition. That is the oldest factor with firearms to date. At the same time, good ideas never truly die, so it is valuable to look back at former ideas and see if there is something we missed and how we can improve in current year.