Let me correct that statement for you:
And yet fully automatic AK-47s and AR-15s are ALMOST NEVER used in committing crime, and the rare instances legally registered Title 2 firearms under the NFA of 1934 were UNLAWFULLY POSSESSED AND USED BY LAW ENFORCEMENT IN THE COMMISSION OF CRIMES.
I used “Never” in a statistical sense.
There may be a handful of crimes committed with them per year. But they fall well under 1%.
As noted upthread, the incidence of long-rifle crime commission is WAY under 5%, and last I read was under 1%. I greatly suspect those numbers are almost all bolt rifles or semi-automatics. The rate of fully automatic rifles among them will be a miniscule fraction.
So, when you get down to a miniscule fraction of a <1% group, you are dealing with a statistical “Never”. Not exactly NONE, but effectively NEVER.
When someone gets around to counting crimes committed by firing fully automatic weapons, I’ll bet there are fewer than TEN per year in the country.