The role of the the hand ax for hunting is explored in
http://www.williamcalvin.com/bk5/bk5ch8.htm
The Acheulean hand ax is far, far older: it was the most
prominent feature of the Acheulean toolkit made by Homo
erectus between 1.5 and 0.3 million years ago. It is found
everywhere
from the tip of Africa to Europe to South
Asia, made of whatever local rocks were handy.
(More "throwing theory" stuff
at http://www.williamcalvin.com/throwing.html ).
Philip Thrift
"Paleofitness"
http://www.paleofitness.com