@YARNLADY Hmm. I think biting the dust refers to the teeth of a human when they are killed and fall forward into the dirt. Homer describes this frequently in The Illiad. Of course the expression if often used just to mean someone is taken down/out, not necessarily to death, nor literally with teeth hitting dirt.
The lyrics seem to be about hunting down a large number of people and killing them with a machinegun, and the lines:
There are plenty of ways you can hurt a man
And bring him to the ground
seem consistent with this, to me.