I remember reading in my NRA magazines in the late 80’s that the ATF would issue notices (scams) that some semi-auto firearms could have the potential to fire more than 1 one round per trigger pull, particularly Browning shotguns. They asked that if you had one to take it to them and they would test it for you. They trapped a couple of folks with this scam and charged them with illegal possession of an automatic weapon. They would load them up with rounds with special primers that would guarantee a double shot.
I had a Baretta A606 semi that would on occasion shoot a double but I kept that to my self.
That IS a scam. The only point in letting them “test” it for you would be if the outcome, should it be one of those, was better than if you had one and they found out about it on their own. Anyone taking theirs in would have to be an idiot.