Republication from livescience.com/

Some of the Roman sling bullets found at the Burnswark Hill battle site in Scotland. The two smallest bullets, shown at the bottom of this image, are drilled with a hole that makes them whistle in flight.
(Image: © John Reid/Trimontium Trust)

Some 1,800 years ago, Roman troops used “whistling” sling bullets as a “terror weapon” against their barbarian foes, according to archaeologists who found the cast lead bullets at a site in Scotland.

Weighing about 1 ounce (30 grams), each of the bullets had been drilled with a 0.2-inch (5 millimeters) hole that the researchers think was designed to give the soaring bullets a sharp buzzing or whistling noise in flight.

The bullets were found recently at Burnswark Hill in southwestern Scotland, where a massive Roman attack against native defenders in a hilltop fort took place in the second century A.D. [See Photos of Roman Battle Site and Sling Bullets]

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