A recent excavation at what is believed to be the site of the first battle of the Roman invasion of Scotland around 140 AD, has uncovered a number of lead slingshot that contained drilled holes.

Approximately 20% of the shot uncovered contained these small holes. This is not the first time that holes have been discovered in Roman slingshot bullets, early theories for the existence of these holes included that they might have been used to hold poison, however recent research has indicated that the holes produce a whistling sound when fired.