I agree with you on a lot of this. I own/use/fire numerous guns. There are many ways we can introduce responsible legislation.
But, to the bolded above, you are being misleading, though maybe not on purpose. There are no current sales of automatic weapons in the public sector with RARE exceptions. If you are making reference to AR-15 style weapons, you have completely overstated the firing rate.
AR-15's are capable of about 600 rounds per minute at the extreme, but that firing rate would melt the barrel. They can sustain between 300-400 rounds per minute, but definitely not with accuracy.
There were workable solutions that received bipartisan approval during the Clinton Admin. Perhaps we should re-visit some of those.