An excavation in Syria appears to have dug up the real thing:

CHICAGO (Jan. 16) - It was the ancient version of a last stand: Twelve clay bullets lined up and ready to be shot from slings in a desperate attempt to stop fierce invaders who soon would reduce much of the city to rubble.

[...]

The site was anything but peaceful in approximately 3,500 B.C. The archaeologists have previously detailed how they believe Hamoukar's independence was ended by a battle that caused its buildings and walls to collapse and burn.

[...]

...along this basin, the researchers found neatly lined up along its edge 12 "sling bullets," oval-shaped weapons made of clay that were fired using slings. More than 1,000 of the bullets were found in debris of collapsed walls in 2005.

Reichel theorizes someone who usually worked with the clay sealings was trying to contribute to the war effort and fashioned bullets from the clay instead.

"You imagine the despair the people were in. They were using everything they could to throw back at the attacker," he said. "It looks like a desperate last attempt."

They can have it when they pry it from my cold dead hands...

AFTERTHOUGHT: I might not be much of a war blogger, I do try to contribute to the war effort, and I urge readers to do likewise.