The .303 is definetly a perennial favorite with aussie hunters, and for good reason! I don't like the old mil ammo, bullet doesn't do any damage, 174 or 215gr Woodleighs kick ass though!
If you are going to reload, you may want to have the chamber reamed out to .303 Epps which is basically the .303 Improved, your brass will last heaps heaps longer and you get a bit more power too! Something to think about...