Do jets breaking the sound barrier leave shredded metal on the ground? As a kid (1960s and 1970s) we would find shredded metal rolled into a loose ball similar to the shredded paper one might find in an Easter basket, in the hills surrounding our farm. We had the Royal Canadian Air Force (RCAF) based about 60 miles north of us in Moose Jaw, Saskatchewan, and the jets used to fly over the farm quite often. We were told that this metal came from the jets when they broke the sound barrier. I can not find any information to confirm this.
I don't think this had anything to do with military jets breaking the sound barrier nearby; it does sound more like strips of metal recovered from chaff dispensers on the jets; countermeasures systems which eject hundreds of strips or threads made of metal foil used to thwart enemy radars.  Most likely the aircraft discharged their chaff dispensers during training exercises over the farm; you simply recovered some of the metal strips.

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