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The lead bullets were about 50 grams each. Strangely, about 10 percent of them contained small holes.
The confused researchers made replicas of several bullets, both holed and solid, and gave it to a trained slinger.
The solid ones flew at up to 100 miles per hour and could hit objects smaller than a human 130 yards away. Furthermore, they contained the stopping power of a .44 magnum, that gun Dirty Harry carried around specifically because it was so powerful.
“The biggest sling stones are very powerful — they could literally take off the top of your head,” Reid told Scientific American.
They also solved the mystery of why some had holes. Those weren’t as effective as a weapon, but they produced “a weird banshee-like wail” as the wind whipped through and over the holes,