Oz customs & confiscated items

It appears, you have to declare them to stay above the board. And there is no 'transit' But still hitting their border and handling in country.. wasnt in these odd hrs was it :P

Baggage is cleared at the first port of entry in Australia.

Exempt: baggage of transit passengers with a destination outside of Australia, if passengers do not leave the transit area.
NOTE: Adelaide (ADL) and Sydney (SYD) are closed between 23:00 and 06:00. Transit passengers must leave the transit area and clear their baggage through Customs.

Passengers traveling from Norfolk Isl. and transiting in mainland Australia must proceed to Australian Border Force (ABF) control and collect their baggage.

Laid out under the arriving/departing area it tends to indicate they can overlap. Importing = requires strict documents etc.

http://www.border.gov.au/Trav/Ente/Goin

But arriving/departing points to declaration

What do I have to declare? Firearms, weapons and ammunition

You must declare all firearms, weapons and ammunition including:

real and imitation firearms
air soft pistols (BB guns) that discharge a pellet by means of compressed gas, commonly purchased as "toy" guns

/edit did you strike this one? http://www.border.gov.au/Factsheets/Documents/travellingwithorsendingfirearmsthroughaustralia-transitandtranshipment-2015.pdf

However it doesn't outlay if airsoft is in the 'associated' field

Firearms and related goods that brought into Australia
and have been or will be transferred from one
conveyance to another for the purposes of export to
another country, such as persons travelling to another
country and changing flights at an Australian international
airport, and sending goods through Australia via air and
sea cargo, are transhipping for the purposes of the Act.

TRANSHIPPING FIREARMS
Firearms and related goods that are being transhipped
through Australia in order to be moved elsewhere are
considered to be imported and exported goods, and are
therefore subject to the requirements under both the
Customs (Prohibited Imports) Regulations 1956 and the
Customs (Prohibited Exports) Regulations 1958.
To meet those requirements the following must occur:
• the goods must only be imported for the purposes of
transhipment; and
• permission to export in the form if a Defence Export
Permit (DEP) must be granted; and
• The goods must remain under the effective control of
ACBPS while in Australia

tchart

loceff13

tchart

graemeh

Oblivian

Zeon