I few Questions

[Dirty Heathen]

When was the first NZ airsoft club formed?

How do shot guns and nade launchers work?

Why are clips/ magazines so expensive the cheapest I have found have been $50 and how many clips do you need per gun?

[EasyGoer]

I can't answer when the first Airsoft club was started in New Zealand, I haven't been in the scene long enough but I am sure someone will come forward and answer that one.
Airsoft Grenade launchers are not like their real world counterparts, they do not launch a grenade that explodes on impact. Generally a grenade is loaded with Gas and BB's and when it is fired it propels the BB's (up to 200 for some grenades) and leaves the grenade in the gun, you wouldn't really want to be hit with a 40mm grenade.
Shotguns generally fire between one and 5 BB's (this varies) per shot and can be gas or spring powered.
I presume you are talking about Gas Blow Back Mags when you ask about the cost. There is a bit more to the mags than meets the eye, they not only hold the BB's but are also a reservoir for the gas used to power the gun. They have o-rings and valves inside them that hold the gas in and release it when required. Unfortunately they do cost a bit. Generally with a GBB (which are the perfect weapons for someone starting out) you need more than one mag (but this is not essential), up to 3 or 4 if you can afford it and will actually use them. As a back up weapon your requirements for the number of mags drops but if it is your primary weapon (which is recommended for new players) then you will need a few more as you are shooting with it alot more often.
I hope that helped answer your questions.

[Dirty Heathen]

cheers

I have just brought a gas Tokyo Marui Desert Eagle which will be my primary weapon for a while so one spare clip should be enough to get by for now?.

I was not very clear on asking about the nade launcher I know they don't fire projectile but wonder how they work as I have seen the BBs being loaded into the shell/nade has the shell its self loaded with gas?

[EasyGoer]

A Desert Eagle wil serve you well as a primary weapon, one spare mag would be ok but if you could afford it you may find you need more or you could end up cowering behind cover somewhere, under heavy fire trying to reload a mag (been there done that). The Grenade from a grenade launcher holds both the BB's and the Gas, when you pull the trigger it opens the valve in the Grenade and launches all the BB's. To use the grenade again you remove it from the launcher, re-prime it with gas and fill up the BB's.

[Dirty Heathen]

Cheers I thought thats how it may work but was not sure.

[Amoki]

How do shot guns and nade launchers work?

By using compressed air - either by spring-cocked mechanism or by a massive compressed gas reservoir. Shotguns eject numerous BBs in one go with the same volume of air. It's similar with airsoft grenade launchers (they shower your traget with a big hail of BBs with one shot).


Why are clips/ magazines so expensive the cheapest I have found have been $50 and how many clips do you need per gun?

As what Easy said. The high cost is associated with the high QC TM usually has to offer.

Pistol mags - you probably only need 1-2 extra during games, pistols often get to become your "backup" weapon when your primary fails/jams/run out of ammo.

But you should really not buy anything until you come to the LOD game. :) (LOD has at least 1 SEG, usually a G36C, in reserve for people new to the club so you will not be using your pistol much.)

[Dirty Heathen]

Sounds good I wont buy any clips for now thanks for your help.