Well, what can you do. I spent 3 months in the U.S. a few years back, and had about $7,500 of airsoft gear I had to leave behind, and a couple of licensed replica 1.77 guns.
But back to Australia... I actually used a pipe cutter on above unit yesterday, and found that it ended up a bit tight (I have a 6mm steel bearing stuck in the end).
However, for $9.95 at Masters (Australian version of Lowes), you can get this: https://www.masters.com.au/product/9000 ... sprayer-6l
It comes with a bonus giant piston inside:
I found the fit a tad too loose for my liking (and not quite short enough), so I grabbed an arrow I had laying about (Gold Tip Expedition Hunter 3555) and lopped off both ends with the same pipe cutter. Replaced the metal sprayer with the arrow, muzzle loaded a 6mm neodynium magnet, gave the piston 10 pumps, pressed the release, and hit myself in the eye (glasses) as it rebounded off a wall :p
Arrow specs: Length: 30" OD: .291" ID: .246"
Bought from http://www.ozhuntingandbows.com.au
(although I bought it in person, they will ship) for $5 or $10 a piece (I forget). Was actually the "default" arrow for the compound bow I bought. They also sell 6mm (and other sized) slingshot ammunition, as well as rubber.
The only thing I am having a hard time finding are actual plastic .20g 6mm airsoft rounds. Seems a bit silly that I can buy 6mm steel bearings, but not 6mm plastic ones. (Or that I can buy a 70 pound compound bow that will go through an interior wall, without even showing a drivers license).
BTW, if you have ever owned a crappy see-through wallmart airsoft gun, then you may recognise some familiar features in this water pistol – which is quite legal to import and maybe available for local sale (never checked)http://www.amazon.com/Saturator-STR60-d ... 003VWCXUO/
I got around to pulling one apart last week, and once you drill out the smaller-sized bits, and rotate the tee from pointing down, to pointing up, you will find everything is amazingly sized at about 6mm and change. Turns out the company who makes them, also make paintball and airsoft guns.