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, - 463 grains), each of the bullets had been drilled with a 0.2-inch (5 mm) hole that the researchers think was designed to give the soaring bullets a sharp buzzing or whistling noise in flight.
These holes converted the bullets into a "terror weapon," said archaeologist John Reid of the Trimontium Trust, a Scottish historical society directing the first major archaeological investigation in 50 years of the Burnswark Hill site.
"You don't just have these silent but deadly bullets flying over; you've got a sound effect coming off them that would keep the defenders' heads down," Reid told Live Science. "Every army likes an edge over its opponents, so this was an ingenious edge on the permutation of sling bullets."
The whistling bullets were also smaller than typical sling bullets, and the researchers think the soldiers may have used several of them in their slings — made from two long cords held in the throwing hand, attached to a pouch that holds the ammunition — so they could hurl multiple bullets at a target with one throw.
Sling bullets and stones are a common find at Roman army battle sites in Europe. The largest are typically shaped like lemons and weigh up to 2 ounces (60 grams), Reid said.
Smaller bullets shaped like acorns — a symbol the Romans considered lucky — have also been found at Burnswark Hill and other sites in Scotland.
About 20 percent of the lead sling bullets found at Burnswark Hill had been drilled with holes, which represented a significant amount of effort to prepare enough ammunition for an assault, Reid said.
At the time of the Roman attack on Burnswark Hill, slings were used mainly by specialized units of auxiliary troops ("auxilia") recruited to fight alongside the Roman legions.
Among the most feared were slingers from the Balearic Islands, an archipelago near Spain in the western Mediterranean, who fought for the Roman general Julius Caesar in his unsuccessful invasions of Britain in 55 B.C. and 54 B.C.
"These guys were expert slingers; they'd been doing this the whole of their lives," Reid said.
In the hands of an expert, a heavy sling bullet or stone could reach speeds of up to 100 mph (160 km/h) = 146.7 feet per second (sub-sonic eh ;-): "The biggest sling stones are very powerful — they could literally take off the top of your head," Reid said.
Roma 3 - Celtic 3
"Scotland is rather like Afghanistan in many respects," Reid said. "The terrain is pretty inhospitable, certainly the farther north you go, and the isolation and long supply lines would make it difficult for servicing an army that far north." (And the locals could fight)
- More ideas for re-loading duplex loads.