I’ve never heard of legit decibel readings for the ftn cans (or any 3dp can I know of lol). The problem is getting ahold of a decibel meter that can measure quick enough pressure impulses, and they are thousands of dollars. Phone microphones just don’t respond fast enough to the microseconds long pressure waves of a gun shot. Would be amazing to develop some sort of diy way to just ballpark it though - maybe some bursting pressure caps of increasing toughness… can’t be that hard considering the big magnitude difference in pressure between even eg 130 and 136 db