Judges 20:16

among all this people are seven hundred chosen men, bound of their right hand, each of these slinging with a stone at the hair, and he doth not err.

Judges 3:15

And the sons of Israel cry unto Jehovah, and Jehovah raiseth to them a saviour, Ehud son of Gera, a Benjamite (a man -- shut of his right hand), and the sons of Israel send by his hand a present to Eglon king of Moab;

1 Chronicles 12:2

armed with bow, right and left handed, with stones, and with arrows, with bows, of the brethren of Saul, of Benjamin.

1 Samuel 17:40

And he taketh his staff in his hand, and chooseth for him five smooth stones from the brook, and putteth them in the shepherds' habiliments that he hath, even in the scrip, and his sling is in his hand, and he draweth nigh unto the Philistine.

1 Samuel 17:49-50

and David putteth forth his hand unto the vessel, and taketh thence a stone, and slingeth, and smiteth the Philistine on his forehead, and the stone sinketh into his forehead, and he falleth on his face to the earth.

1 Samuel 25:29

And man riseth to pursue thee and to seek thy soul, and the soul of my lord hath been bound in the bundle of life with Jehovah thy God; as to the soul of thine enemies, He doth sling them out in the midst of the hollow of the sling.

2 Chronicles 26:14

And Uzziah prepareth for them, for all the host, shields, and spears, and helmets, and coats of mail, and bows, even to stones of the slings.

Treasury of Scripture Knowledge

Summary

Among all this people there were seven hundred chosen men lefthanded; every one could sling stones at an hair breadth, and not miss.

Bible References

Left-handed

Judges 3:15
And the sons of Israel cry unto Jehovah, and Jehovah raiseth to them a saviour, Ehud son of Gera, a Benjamite (a man -- shut of his right hand), and the sons of Israel send by his hand a present to Eglon king of Moab;
1 Chronicles 12:2
armed with bow, right and left handed, with stones, and with arrows, with bows, of the brethren of Saul, of Benjamin.

Sling stones

1 Samuel 17:40
And he taketh his staff in his hand, and chooseth for him five smooth stones from the brook, and putteth them in the shepherds' habiliments that he hath, even in the scrip, and his sling is in his hand, and he draweth nigh unto the Philistine.
1 Samuel 25:29
And man riseth to pursue thee and to seek thy soul, and the soul of my lord hath been bound in the bundle of life with Jehovah thy God; as to the soul of thine enemies, He doth sling them out in the midst of the hollow of the sling.
2 Chronicles 26:14
And Uzziah prepareth for them, for all the host, shields, and spears, and helmets, and coats of mail, and bows, even to stones of the slings.