They also used actual military tactics to fight the Emus, like mapping their routes and setting up ambushes. In one of these, they managed to get close to a flock of about a thousand emus and attacked them with machine guns only allowing the escape of... lemme check... about a thousand emus.
I typically have a 60% accuracy in Helldivers 2 and I'm fighting swarms of giant bugs. I think I'll forgive the Australians for 10 rounds per bird, especially since winging an emu probably doesn't stop it.
Compared to the amount of bullets expended per casualty in any modern war that is actually very good.
The US probably fired thousands of bullets for each insurgent killed in Iraq or Afghanistan.