I would have assumed they just took it out to a safe enough area and put it in a pile, maybe with some wood and accelerant, get back a safe distance, and set it ablaze. When the cartridges are not supported by a firearm chamber, the case will rupture. No need to worry about bullets flying out at a 1,000 fps.

Breaking them down to salvage the components would be impractical if tens of thousands must be disposed of.

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