Albert Barnes Commentary 2 Chronicles 26:14

"And Uzziah prepared for them, even for all the host, shields, and spears, and helmets, and coats of mail, and bows, and stones for slinging." — 2 Chronicles 26:14 (ASV)

The sling was used in war by the Assyrians, the Egyptians, the Persians, the Greeks, Romans, and others. Its use by the Benjamites is shown in Judges 20:16, and by the ten tribes, a century before Uzziah, in 2 Kings 3:25.