back to the action of the arrow on your piece of steel, a chap by the name of Colin Ledsome who was a lecturer in mechanical engineering arranged a session for a film crew and to shoot some arrows for them at various objects such as steel, armoured glass etc. The slow mo filming showed the shaft flexing considerably after the impact had caused the arrow to halt its forward motion and this flexing made the arrow behave like a hammer drill and so they then penetrated the armour they were shot at. The energy absorbing properties of laminated anti-bandit glass would stop a bullet or blast from a shotgun but the arrow drilled through it. He had advised that they didint stand behind the targets and initially they took a bit of persuading not to and to use remote cameras. they were very glad afterwards they had done as suggested.