Need help with headstamp

I’m new to bullets. Like collecting but don’t really know much. I’m form asutralia and just bought some 50 bmg which are hard to get over here. The headstamps say “ADI 03” I would just like to know what that means.

ADI = Australian Defense Industry (manufacturer)
03 = 2003 (date of manufacturer)

Where in Aus?

Thanks for that 🙂 and I’m form south Australia