any places for duck hunting Sydney?

I believe that netting birds of any description is illegal in all states and territories within Australia without a proper permit (not a hunting permit). Also season, species and bag limits apply to states that do allow waterfowl hunting.

A "net gun" would be classed as a firearm, however I'm mot sure what category it would be in. You would also have to carry a licence in order to posses and use such a device.

The short answer is "no"

Space Cowboy- those regs are for deer. That's a totally different taxa of animal.

What do your local NSW Hunting regulations have to say about it ? You DID get a copy and read them...yes ?

I believe only licenced bird ringers are allowed to use net mortars !

And not for hunting purposes!