In A Nutshell
Many people assume boomerangs are for throwing directly at animals during hunting, with the assumption that if you missed, the boomerang would return and you would get another shot. But that’s incorrect: they were actually used to imitate hawks.
The Whole Bushel
First, there was more than one type of boomerang, and not all them could return to the thrower. The most common boomerang was larger and heavier than the type most common in pop culture. These larger boomerangs were perfect for hunting. They didn’t return to the thrower, but their weight enabled them to be thrown accurately and quickly at larger game. They were essentially just thrown directly at an animal, with a direct hit hard enough to kill or stun it long enough to be caught.
They were even used in battle. It’s believed that the return boomerang was actually discovered by accident, through years of modifications to the hunting boomerangs in attempt to make them faster and less affected by wind.
The smaller return boomerangs however are terrible for hunting in the way described above. They weighed too little to do any real damage to large animals and were much more difficult to throw accurately. Instead they were often used to drive game birds into nets. The boomerang would be thrown above the flock and, mistaking it for a larger predator, they would flee and inadvertently fly right into the nets set up by the hunters. In many cases, the hunter group would imitate the calls of a hawk to increase the chance the birds would take flight. Very skilled throwers could even have the boomerang skim the top of the trees where the birds were located, scaring them and again forcing them into traps.
Show Me The Proof
Aerodynamics of a Boomerang
How Boomerangs Work