How about if David used a bigger stone?

Answer 1

David was quite adept at using a sling shot. The giant Goliath was struck in the forehead by the stone and it sunk into his skull. There is a weak spot in giants in the forehead. Using a bigger stone or smaller stone would not alter the result because David slew Goliath by moving in the anointing that God had put on his life.

Goliath mocked the armies of the living God for 40 days. David was not just talented. David was a man anointed by the Spirit of God. David killed the lions and bears that had attacked the sheep that he cared for with the power of the anointing of God. It was that experience and confidence in God that caused David to successfully hurl the stone and knock down the giant. He then cut off the giant's head with the giant's own sword.

The rest of the Philistines went running, not because they were now afraid of David, but because they were afraid of the God of David.