Wow, slam fire full auto = prison? WTF.

No info if it was the guy who borrowed or some other asshat that rolled on him. That's part of the travesty. That another gun owner, possibly someone that either ran their own loads or some crap .223 junk with soft primers, turned on this guy.

“By this time, the weapon had been in the hands of the ATF for four
months. What caused the functional change in the weapon to fire as it had not done
before is unknown, although the ATF agent did acknowledge that the change in the
outcome from the October test resulted from a change to ‘softer primer’
ammunition,” the appellate documents said.