Why can’t i find any online shops that have toy guns in Australia?

I want to make a short action film but one problem i dont know where i can get toy machine guns or sub machine guns. I have looked on usa online shops for toy guns but they don't ship to Australia. I've tried ebay Australia they only have water guns. Please help me?

What are some of the most outrageous weapons you can buy in America?

I've heard you can buy an Anti-tank gun in texas? (I'm from Australia where it is ridiculously hard to own a gun)